# Draft California 2012 Integrated Report( 303(d) List/305(b) Report)

# Supporting Information

## Regional Board 6 - Lahontan Region

Water Body Name: | Mesquite Springs (Inyo County)
Water Body ID: | CAW6091100020080825153033
Water Body Type: | Wetland, Freshwater

DECISION ID | 20859 | Region 6
Mesquite Springs (Inyo County)

Pollutant: | Alkalinity, Carbonate as CaCO3
Final Listing Decision: | Do Not List on 303(d) list (TMDL required list)
Last Listing Cycle's Final Listing Decision: | Do Not List on 303(d) list (TMDL required list)(2010)
Revision Status | Original
Impairment from Pollutant or Pollution: | Pollutant
Regional Board Staff Conclusion: | This pollutant was considered for placement on the section 303(d) list in a previous assessment cycle. No new information was reviewed for this current assessment cycle. Therefore, the previous conclusion remains unchanged, and is as follows: This pollutant is being considered for placement on the section 303(d) list under section 3.2 of the Listing Policy. Under section 3.2 a single line of evidence is necessary to assess listing status. One line of evidence is available in the administrative record to assess this pollutant. None of the samples exceed the water quality criterion. However, only two samples were available and this does not meet the minimum sample number requirement of Listing Policy Table 3.2. Based on the readily available data and information, the weight of evidence indicates that there is sufficient justification against placing this water segment-pollutant combination on the section 303(d) list in the Water Quality Limited Segments category. Pursuant to section 3.11 of the Listing Policy, no additional data and information are available indicating that standards are not met.
Regional Board Staff Decision Recommendation: | No new data were assessed for this assessment cycle. The conclusion reached in the previous cycle remains in same. The Regional Board will update this decision when new data and information become available in a future assessment cycle.

Line of Evidence (LOE) for Decision ID 20859, Alkalinity, Carbonate as CaCO3 | Region 6
Mesquite Springs (Inyo County)
LOE ID: | 6042
Pollutant: | Alkalinity, Carbonate as CaCO3
LOE Subgroup: | Pollutant-Water
Matrix: | Water
Fraction: | None
Beneficial Use: | Cold Freshwater Habitat
Number of Samples: | 2
Number of Exceedances: | 0
Data and Information Type: | Fixed station physical/chemical (conventional plus toxic pollutants)
Data Used to Assess Water Quality: | The U.S. Geological Survey sampled Mesquite Springs under the Region 6 SWAMP program in 2002 and 2003. Two samples were taken for alkalinity. One result was an estimated 326 mg/L and the other was 353 mg/L. The chronic criterion was not exceeded.
Data Reference: | 2007. SWAMP Data for the Amargosa Hydrologic Unit
SWAMP Data: | SWAMP
Water Quality Objective/Criterion: | The USEPA's national water quality criteria recommend a minimum hardness of 20 mg/L calcium carbonate as a chronic criterion for the protection of aquatic life, unless the natural alkalinity level is lower.
Objective/Criterion Reference: | National Recommended Water Quality Criteria. United States Environmental Protection Agency. Office of Water. Office of Science and Technology
Evaluation Guideline: |
Guideline Reference:
Spatial Representation: | One station, Mesquite Spring (in Death Valley National Park, near Scottys Castle), was sampled.
Temporal Representation: | Two samples were collected in 2002 and 2003.
Environmental Conditions: | The Mesquite Springs are within the Stovepipe Wells Hydrologic Subarea of the Amargosa Hydrologic Unit (HU No. 609.11). They supply drinking water to a campground. No site-specific water quality objectives apply to the springs. Chemical and radioactive constituents come from natural sources.
QAPP Information: | Data meet the quality assurance requirements of the SWAMP QAPP.
QAPP Information Reference(s):

DECISION ID | 28155 | Region 6
Mesquite Springs (Inyo County)

Pollutant: | Aluminum
Final Listing Decision: | Do Not List on 303(d) list (TMDL required list)
Last Listing Cycle's Final Listing Decision: | Do Not List on 303(d) list (TMDL required list)(2010)
Revision Status | Original
Impairment from Pollutant or Pollution: | Pollutant
Regional Board Staff Conclusion: | This pollutant was considered for placement on the section 303(d) list in a previous assessment cycle. No new information was reviewed for this current assessment cycle. Therefore, the previous conclusion remains unchanged, and is as follows: This pollutant is being considered for placement on the section 303(d) list under section 3.1 of the Listing Policy. Under section 3.1 a single line of evidence is necessary to assess listing status. Two lines of evidence are available in the administrative record to assess this pollutant. None of the samples exceeds the water quality objective. Based on the readily available data and information, the weight of evidence indicates that there is sufficient justification against placing this water segment-pollutant combination on the section 303(d) list in the Water Quality Limited Segments category. This conclusion is based on the staff findings that: 1. The data used satisfy the data quality requirements of section 6.1.4 of the Policy. 2. The data used do not satisfy the data quantity requirements of section 6.1.5 of the Policy in that only one sample per year is available. 3. Neither of two samples exceeded the applicable water quality objective and aquatic life criterion, and this does not exceed the allowable frequency listed in Table 3.1 of the Listing Policy. 4. Pursuant to section 3.11 of the Listing Policy, no additional data and information are available indicating that standards are not met.
Regional Board Staff Decision Recommendation: | No new data were assessed for this assessment cycle. The conclusion reached in the previous cycle remains in same. The Regional Board will update this decision when new data and information become available in a future assessment cycle.

Line of Evidence (LOE) for Decision ID 28155, Aluminum | Region 6
Mesquite Springs (Inyo County)
LOE ID: | 5484
Pollutant: | Aluminum
LOE Subgroup: | Pollutant-Water
Matrix: | Water
Fraction: | Dissolved
Beneficial Use: | Municipal & Domestic Supply
Number of Samples: | 2
Number of Exceedances: | 0
Data and Information Type: | Fixed station physical/chemical (conventional plus toxic pollutants)
Data Used to Assess Water Quality: | The U.S. Geological Survey sampled Mesquite Springs under the Region 6 SWAMP program in 2002 and 2003.
Data Reference: | 2007. SWAMP Data for the Amargosa Hydrologic Unit
SWAMP Data: | SWAMP
Water Quality Objective/Criterion: | California Maximum Contaminant Levels (MCLs) apply to ambient waters under the Lahontan Basin Plan's "Chemical Constituents" objective. The primary MCL for aluminum is 1000 ug/L, and the secondary MCL is 200 ug/L. Concentrations of dissolved aluminum in two samples were both estimates. The MCLs were not exceeded.
Objective/Criterion Reference: | Water Quality Control Plan for the Lahontan Region (as amended)
Evaluation Guideline: |
Guideline Reference:
Spatial Representation: | One station, Mesquite Spring (in Death Valley National Park, near Scottys Castle), was sampled.
Temporal Representation: | Two samples were collected in 2002 and 2003.
Environmental Conditions: | The Mesquite Springs are within the Stovepipe Wells Hydrologic Subarea of the Amargosa Hydrologic Unit (HU No. 609.11). They supply drinking water to a campground. No site-specific water quality objectives apply to the springs. Chemical and radioactive constituents come from natural sources.
QAPP Information: | Data meet the quality assurance requirements of the SWAMP QAPP.
QAPP Information Reference(s):
Line of Evidence (LOE) for Decision ID 28155, Aluminum | Region 6
Mesquite Springs (Inyo County)
LOE ID: | 5744
Pollutant: | Aluminum
LOE Subgroup: | Pollutant-Water
Matrix: | Water
Fraction: | Dissolved
Beneficial Use: | Cold Freshwater Habitat
Number of Samples: | 2
Number of Exceedances: | 0
Data and Information Type: | Fixed station physical/chemical (conventional plus toxic pollutants)
Data Used to Assess Water Quality: | The U.S. Geological Survey sampled Mesquite Springs under the Region 6 SWAMP program in 2002 and 2003. Two samples for dissolved aluminum were both estimated values. The USEPA aquatic life criterion was not exceeded.
Data Reference: | 2007. SWAMP Data for the Amargosa Hydrologic Unit
SWAMP Data: | SWAMP
Water Quality Objective/Criterion: | The U.S. Environmental Protection Agency (USEPA) 4-day average freshwater aquatic life criterion for aluminum is 87 ug/L.
Objective/Criterion Reference: | National recommended water quality criteria: 2002. EPA-822-R-02-047 Washington, D.C. USEPA
Evaluation Guideline: |
Guideline Reference:
Spatial Representation: | One station, Mesquite Spring (in Death Valley National Park, near Scottys Castle), was sampled.
Temporal Representation: | Two samples were collected in 2002 and 2003.
Environmental Conditions: | The Mesquite Springs are within the Stovepipe Wells Hydrologic Subarea of the Amargosa Hydrologic Unit (HU No. 609.11). They supply drinking water to a campground. No site-specific water quality objectives apply to the springs. Chemical and radioactive constituents come from natural sources.
QAPP Information: | Data meet the quality assurance requirements of the SWAMP QAPP.
QAPP Information Reference(s):

DECISION ID | 20787 | Region 6
Mesquite Springs (Inyo County)

Pollutant: | Antimony
Final Listing Decision: | Do Not List on 303(d) list (TMDL required list)
Last Listing Cycle's Final Listing Decision: | Do Not List on 303(d) list (TMDL required list)(2010)
Revision Status | Original
Impairment from Pollutant or Pollution: | Pollutant
Regional Board Staff Conclusion: | This pollutant was considered for placement on the section 303(d) list in a previous assessment cycle. No new information was reviewed for this current assessment cycle. Therefore, the previous conclusion remains unchanged, and is as follows: This pollutant is being considered for placement on the section 303(d) list under section 3.2 of the Listing Policy. Under section 3.1 a single line of evidence is necessary to assess listing status. Two lines of evidence are available in the administrative record to assess this pollutant. None of the samples exceeds the applicable standard and criteria. Based on the readily available data and information, the weight of evidence indicates that there is sufficient justification against placing this water segment-pollutant combination on the section 303(d) list in the Water Quality Limited Segments category. This conclusion is based on the staff findings that: 1. The data used satisfy the data quality requirements of section 6.1.4 of the Policy. 2. The data used do not satisfy the data quantity requirements of section 6.1.5 of the Policy in that only one sample per year is available. 3. Neither of two samples exceeded the applicable objective and criteria and this does not exceed the allowable frequency listed in Table 3.2 of the Listing Policy. 4. Pursuant to section 3.11 of the Listing Policy, no additional data and information are available indicating that standards are not met.
Regional Board Staff Decision Recommendation: | No new data were assessed for this assessment cycle. The conclusion reached in the previous cycle remains in same. The Regional Board will update this decision when new data and information become available in a future assessment cycle.

Line of Evidence (LOE) for Decision ID 20787, Antimony | Region 6
Mesquite Springs (Inyo County)
LOE ID: | 6041
Pollutant: | Antimony
LOE Subgroup: | Pollutant-Water
Matrix: | Water
Fraction: | Dissolved
Beneficial Use: | Cold Freshwater Habitat
Number of Samples: | 2
Number of Exceedances: | 0
Data and Information Type: | Fixed station physical/chemical (conventional plus toxic pollutants)
Data Used to Assess Water Quality: | The U.S. Geological Survey sampled Mesquite Springs under the Region 6 SWAMP program in 2002 and 2003. Dissolved antimony concentrations in two samples were 1.1 and 0.92 ug/L. The USEPA aquatic life criteria were not exceeded.
Data Reference: | 2007. SWAMP Data for the Amargosa Hydrologic Unit
SWAMP Data: | SWAMP
Water Quality Objective/Criterion: | The U.S. Environmental Protection Agency's (USEPA's) Lowest Observed Effect Levels (LOELs) criteria are as follows: Acute toxicity = 9000 ug/L; Chronic toxicity = 1600 ug/L. The USEPA criterion for toxicity to algae = 610 ug/L.
Objective/Criterion Reference: | National Recommended Water Quality Criteria. United States Environmental Protection Agency. Office of Water. Office of Science and Technology
Evaluation Guideline: |
Guideline Reference:
Spatial Representation: | One station, Mesquite Spring (in Death Valley National Park, near Scottys Castle), was sampled.
Temporal Representation: | Two samples were collected in 2002 and 2003.
Environmental Conditions: | The Mesquite Springs are within the Stovepipe Wells Hydrologic Subarea of the Amargosa Hydrologic Unit (HU No. 609.11). They supply drinking water to a campground. No site-specific water quality objectives apply to the springs. Chemical and radioactive constituents come from natural sources.
QAPP Information: | Data meet the quality assurance requirements of the SWAMP QAPP.
QAPP Information Reference(s):
Line of Evidence (LOE) for Decision ID 20787, Antimony | Region 6
Mesquite Springs (Inyo County)
LOE ID: | 5315
Pollutant: | Antimony
LOE Subgroup: | Pollutant-Water
Matrix: | Water
Fraction: | Dissolved
Beneficial Use: | Municipal & Domestic Supply
Number of Samples: | 2
Number of Exceedances: | 0
Data and Information Type: | Fixed station physical/chemical (conventional plus toxic pollutants)
Data Used to Assess Water Quality: | The U.S. Geological Survey sampled Mesquite Springs under the Region 6 SWAMP program in 2002 and 2003. Dissolved antimony concentrations in two samples were 1.1 and 0.92 ug/L.The MCL was not exceeded. (Note: MCLs for metals are expressed as total rather than dissolved.)
Data Reference: | 2007. SWAMP Data for the Amargosa Hydrologic Unit
SWAMP Data: | SWAMP
Water Quality Objective/Criterion: | California Maximum Contaminant Levels (MCLs) apply to ambient waters under the Lahontan Basin Plan's "Chemical Constituents" objective. The MCL for antimony is 6 ug/L.
Objective/Criterion Reference: | Water Quality Control Plan for the Lahontan Region (as amended)
Evaluation Guideline: |
Guideline Reference:
Spatial Representation: | One station, Mesquite Spring (in Death Valley National Park, near Scottys Castle), was sampled.
Temporal Representation: | Two samples were collected in 2002 and 2003.
Environmental Conditions: | The Mesquite Springs are within the Stovepipe Wells Hydrologic Subarea of the Amargosa Hydrologic Unit (HU No. 609.11). They supply drinking water to a campground. No site-specific water quality objectives apply to the springs. Chemical and radioactive constituents come from natural sources.
QAPP Information: | Data meet the quality assurance requirements of the SWAMP QAPP.
QAPP Information Reference(s):

DECISION ID | 20752 | Region 6
Mesquite Springs (Inyo County)

Pollutant: | Barium
Final Listing Decision: | Do Not List on 303(d) list (TMDL required list)
Last Listing Cycle's Final Listing Decision: | Do Not List on 303(d) list (TMDL required list)(2010)
Revision Status | Original
Impairment from Pollutant or Pollution: | Pollutant
Regional Board Staff Conclusion: | This pollutant was considered for placement on the section 303(d) list in a previous assessment cycle. No new information was reviewed for this current assessment cycle. Therefore, the previous conclusion remains unchanged, and is as follows: This pollutant is being considered for placement on the section 303(d) list under section 3.1 of the Listing Policy. Under section 3.1 a single line of evidence is necessary to assess listing status. One line of evidence is available in the administrative record to assess this pollutant. None of the samples exceeds the water quality objective. Based on the readily available data and information, the weight of evidence indicates that there is sufficient justification against placing this water segment-pollutant combination on the section 303(d) list in the Water Quality Limited Segments category. This conclusion is based on the staff findings that: 1. The data used satisfy the data quality requirements of section 6.1.4 of the Policy. 2. The data used do not satisfy the data quantity requirements of section 6.1.5 of the Policy in that only one sample per year is available. 3. Neither of two samples exceeded the water quality objective and this does not exceed the allowable frequency listed in Table 3.1 of the Listing Policy. 4. Pursuant to section 3.11 of the Listing Policy, no additional data and information are available indicating that standards are not met.
Regional Board Staff Decision Recommendation: |

Line of Evidence (LOE) for Decision ID 20752, Barium | Region 6
Mesquite Springs (Inyo County)
LOE ID: | 5272
Pollutant: | Barium
LOE Subgroup: | Pollutant-Water
Matrix: | Water
Fraction: | Dissolved
Beneficial Use: | Municipal & Domestic Supply
Number of Samples: | 2
Number of Exceedances: | 0
Data and Information Type: | Fixed station physical/chemical (conventional plus toxic pollutants)
Data Used to Assess Water Quality: | The U.S. Geological Survey sampled Mesquite Springs under the Region 6 SWAMP program. Dissolved barium concentrations in two samples were 22 and 23 ug/L. The MCL was not exceeded
Data Reference: | 2007. SWAMP Data for the Amargosa Hydrologic Unit
SWAMP Data: | SWAMP
Water Quality Objective/Criterion: | California Maximum Contaminant Levels (MCLs) apply to ambient waters under the Lahontan Basin Plan's "Chemical Constituents" objective. The California MCL for barium is 1000 ug/L.
Objective/Criterion Reference: | Water Quality Control Plan for the Lahontan Region (as amended)
Evaluation Guideline: |
Guideline Reference:
Spatial Representation: | One station, Mesquite Spring (in Death Valley National Park, near Scottys Castle), was sampled.
Temporal Representation: | Two samples were collected in 2002 and 2003.
Environmental Conditions: | The Mesquite Springs are within the Stovepipe Wells Hydrologic Subarea of the Amargosa Hydrologic Unit (HU No. 609.11). They supply drinking water to a campground. No site-specific water quality objectives apply to the springs. Chemical and radioactive constituents come from natural sources.
QAPP Information: | Data meet the quality assurance requirements of the SWAMP QAPP.
QAPP Information Reference(s):

DECISION ID | 23033 | Region 6
Mesquite Springs (Inyo County)

Pollutant: | Beryllium | Iron | Lead | Silver | Thallium
Final Listing Decision: | Do Not List on 303(d) list (TMDL required list)
Last Listing Cycle's Final Listing Decision: | Do Not List on 303(d) list (TMDL required list)(2010)
Revision Status | Original
Impairment from Pollutant or Pollution: | Pollutant
Regional Board Staff Conclusion: | This pollutant was considered for placement on the section 303(d) list in a previous assessment cycle. No new information was reviewed for this current assessment cycle. Therefore, the previous conclusion remains unchanged, and is as follows: These pollutants are being considered for placement on the section 303(d) list under section 3.1 of the Listing Policy. Under section 3.1 a single line of evidence is necessary to assess listing status. Two lines of evidence are available in the administrative record to assess these pollutants. None of the samples for any of the pollutants exceeds the applicable water quality criteria, California Toxics Rule standards, or California Maximum Contaminant Levels. All metals concentrations were at nondetectable levels. Under Listing Policy 6.1.5.5, the standards and criteria are presumed to be attained. Based on the readily available data and information, the weight of evidence indicates that there is sufficient justification against placing this water segment-pollutant combination on the section 303(d) list in the Water Quality Limited Segments category. This conclusion is based on the staff findings that: 1. The data used satisfy the data quality requirements of section 6.1.4 of the Policy. 2. The data used do not satisfy the data quantity requirements of section 6.1.5 of the Policy in that only one sample per year is available. 3. None of the two samples for each pollutant exceeded the applicable standard or criterion and this does not exceed the allowable frequency listed in Table 3.1 of the Listing Policy. 4. Pursuant to section 3.11 of the Listing Policy, no additional data and information are available indicating that standards are not met.
Regional Board Staff Decision Recommendation: | No new data were assessed for this assessment cycle. The conclusion reached in the previous cycle remains in same. The Regional Board will update this decision when new data and information become available in a future assessment cycle.

Line of Evidence (LOE) for Decision ID 23033, Multiple Pollutants | Region 6
Mesquite Springs (Inyo County)
LOE ID: | 5275
Pollutant: | Beryllium | Iron | Lead | Silver | Thallium
LOE Subgroup: | Pollutant-Water
Matrix: | Water
Fraction: | Dissolved
Beneficial Use: | Municipal & Domestic Supply
Number of Samples: | 2
Number of Exceedances: | 0
Data and Information Type: | Not Specified
Data Used to Assess Water Quality: | The U.S. Geological Survey sampled Mesquite Springs under the Region 6 SWAMP program. Sampling results for the metals above were below detection levels. Per listing policy Section 6.1.5.5 the standards and criteria are resumed to be attained.
Data Reference: | 2007. SWAMP Data for the Amargosa Hydrologic Unit
SWAMP Data: | SWAMP
Water Quality Objective/Criterion: | California Maximum Contaminant Levels (MCLs) apply to ambient waters under the Lahontan Basin Plan's "Chemical Constituents" objective. The MCLs for the listed pollutants are as follows: beryllium, 4 ug/L; iron, 300 ug/L; lead, 15 ug/L; silver, 100 ug/L; thallium, 2 ug/L.
Objective/Criterion Reference: | Water Quality Control Plan for the Lahontan Region (as amended)
Evaluation Guideline: |
Guideline Reference:
Spatial Representation: | One station, Mesquite Spring (in Death Valley National Park, near Scottys Castle), was sampled.
Temporal Representation: | Two samples were collected for each metal in 2002 and 2003.
Environmental Conditions: | The Mesquite Springs are within the Stovepipe Wells Hydrologic Subarea of the Amargosa Hydrologic Unit (HU No. 609.11). They supply drinking water to a campground. No site-specific water quality objectives apply to the springs. Chemical and radioactive constituents, including metals, come from natural sources.
QAPP Information: | Data meet the quality assurance requirements of the SWAMP QAPP.
QAPP Information Reference(s):
Line of Evidence (LOE) for Decision ID 23033, Multiple Pollutants | Region 6
Mesquite Springs (Inyo County)
LOE ID: | 5792
Pollutant: | Beryllium | Iron | Lead | Silver | Thallium
LOE Subgroup: | Pollutant-Water
Matrix: | Water
Fraction: | Dissolved
Beneficial Use: | Cold Freshwater Habitat
Number of Samples: | 2
Number of Exceedances: | 0
Data and Information Type: | Fixed station physical/chemical (conventional plus toxic pollutants)
Data Used to Assess Water Quality: | The U.S. Geological Survey sampled Mesquite Springs under the Region 6 SWAMP program. Sampling results for the metals above were below detection levels. Per listing policy Section 6.1.5.5 the standards and criteria are resumed to be attained.
Data Reference: | 2007. SWAMP Data for the Amargosa Hydrologic Unit
SWAMP Data: | SWAMP
Water Quality Objective/Criterion: | The applicable U.S. Environmental Protection Agency freshwater aquatic life criteria are as follows. For beryllium, the acute criterion is 130 ug/L and the chronic criterion is 5.3 ug/L. For iron, the 4- day average criterion is 1000 ug/L. For thallium, the acute Lowest Observed Effect Level (LOEL) criterion is 1400 ug/L, and the chronic LOEL criterion is 40 ug/L. (An "Other" criterion for thallium is 20 ug/L.) The California Toxics Rule (CTR) aquatic life standards for lead and silver are dependent on hardness. At the reported hardness values (123 and 126 mg/L CaCO3) the CTR standards are as follows. For lead, the acute standards are 84.05 and 86.67 ug/L. The chronic standards are 3.28 and 3..38 ug/L. For silver, the standard is 4.93 and 4.13 ug/L.
Objective/Criterion Reference: | National recommended water quality criteria: 2002. EPA-822-R-02-047 Washington, D.C. USEPA
| Water Quality Standards 2000. Establishment of numeric criteria for priority toxic pollutants for the State of California: Rules and regulations. Federal Register Vol. 65, No. 97. Washington, D.C.: Environmental Protection Agency
| Quality Criteria for Water 1986. United States Environmental Protection Agency. Office of Water. Regulations and Standards. Washington D.C. EPA 440/5-86-001.
Evaluation Guideline: |
Guideline Reference:
Spatial Representation: | One station, Mesquite Spring (in Death Valley National Park, near Scottys Castle), was sampled.
Temporal Representation: | Two samples were collected for each metal in 2002 and 2003.
Environmental Conditions: | The Mesquite Springs are within the Stovepipe Wells Hydrologic Subarea of the Amargosa Hydrologic Unit (HU No. 609.11). They supply drinking water to a campground. No site-specific water quality objectives apply to the springs. Chemical and radioactive constituents, including metals, come from natural sources.
QAPP Information: | Data meet the quality assurance requirements of the SWAMP QAPP.
QAPP Information Reference(s):

DECISION ID | 20907 | Region 6
Mesquite Springs (Inyo County)

Pollutant: | Cadmium
Final Listing Decision: | Do Not List on 303(d) list (TMDL required list)
Last Listing Cycle's Final Listing Decision: | Do Not List on 303(d) list (TMDL required list)(2010)
Revision Status | Original
Impairment from Pollutant or Pollution: | Pollutant
Regional Board Staff Conclusion: | This pollutant was considered for placement on the section 303(d) list in a previous assessment cycle. No new information was reviewed for this current assessment cycle. Therefore, the previous conclusion remains unchanged, and is as follows: This pollutant is being considered for placement on the section 303(d) list under section 3.1 of the Listing Policy. Under section 3.1 a single line of evidence is necessary to assess listing status. Two lines of evidence are available in the administrative record to assess this pollutant. Neither of the samples exceeds the water quality objective.or California Toxics Rule standards. Based on the readily available data and information, the weight of evidence indicates that there is sufficient justification against placing this water segment-pollutant combination on the section 303(d) list in the Water Quality Limited Segments category. This conclusion is based on the staff findings that: 1. The data used satisfy the data quality requirements of section 6.1.4 of the Policy. 2. The data used do not satisfy the data quantity requirements of section 6.1.5 of the Policy in that only one sample per year is available. 3. Neither of two samples exceeded the applicable standards and this does not exceed the allowable frequency listed in Table 3.1 of the Listing Policy. 4. Pursuant to section 3.11 of the Listing Policy, no additional data and information are available indicating that standards are not met.
Regional Board Staff Decision Recommendation: | No new data were assessed for this assessment cycle. The conclusion reached in the previous cycle remains in same. The Regional Board will update this decision when new data and information become available in a future assessment cycle.

Line of Evidence (LOE) for Decision ID 20907, Cadmium | Region 6
Mesquite Springs (Inyo County)
LOE ID: | 5308
Pollutant: | Cadmium
LOE Subgroup: | Pollutant-Water
Matrix: | Water
Fraction: | Dissolved
Beneficial Use: | Cold Freshwater Habitat
Number of Samples: | 2
Number of Exceedances: | 0
Data and Information Type: | Fixed station physical/chemical (conventional plus toxic pollutants)
Data Used to Assess Water Quality: | The U.S. Geological Survey sampled Mesquite Springs under the Region 6 SWAMP program. Dissolved cadmium concentrations in two samples were 0.4 and 0.5 ug/L. The California Toxics Rule standards were not exceeded.
Data Reference: | 2007. SWAMP Data for the Amargosa Hydrologic Unit
SWAMP Data: | SWAMP
Water Quality Objective/Criterion: | The California Toxics Rule cadmium standard for protection of freshwater aquatic life is hardness-based. At the recorded hardness levels, the acute toxicity standard ranges from 5.39 to 5.53 ug/L The chronic toxicity standard ranges from 2.63 to 2.6 ug/L.
Objective/Criterion Reference: | Water Quality Standards 2000. Establishment of numeric criteria for priority toxic pollutants for the State of California: Rules and regulations. Federal Register Vol. 65, No. 97. Washington, D.C.: Environmental Protection Agency
| Water Quality Control Plan for the Lahontan Region (as amended)
Evaluation Guideline: |
Guideline Reference:
Spatial Representation: | One station, Mesquite Spring (in Death Valley National Park, near Scottys Castle), was sampled.
Temporal Representation: | Two samples were collected in 2002 and 2003.
Environmental Conditions: | The Mesquite Springs are within the Stovepipe Wells Hydrologic Subarea of the Amargosa Hydrologic Unit (HU No. 609.11). They supply drinking water to a campground. No site-specific water quality objectives apply to the springs. Chemical and radioactive constituents come from natural sources.
QAPP Information: | Data meet the quality assurance requirements of the SWAMP QAPP.
QAPP Information Reference(s):
Line of Evidence (LOE) for Decision ID 20907, Cadmium | Region 6
Mesquite Springs (Inyo County)
LOE ID: | 5741
Pollutant: | Cadmium
LOE Subgroup: | Pollutant-Water
Matrix: | Water
Fraction: | Dissolved
Beneficial Use: | Municipal & Domestic Supply
Number of Samples: | 2
Number of Exceedances: | 0
Data and Information Type: | Fixed station physical/chemical (conventional plus toxic pollutants)
Data Used to Assess Water Quality: | The U.S. Geological Survey sampled Mesquite Springs under the Region 6 SWAMP program. Dissolved cadmium concentrations in two samples were 0.4 and 0.5 ug/L. The MCL was not exceeded. (Note: MCLs for metals are expressed as total rather than dissolved, but total cadmium data were not available.)
Data Reference: | 2007. SWAMP Data for the Amargosa Hydrologic Unit
SWAMP Data: | SWAMP
Water Quality Objective/Criterion: | California Maximum Contaminant Levels (MCLs) apply to ambient waters under the Lahontan Basin Plan's "Chemical Constituents" objective. The MCL for cadmium is 5 ug/L.
Objective/Criterion Reference: | Water Quality Control Plan for the Lahontan Region (as amended)
Evaluation Guideline: |
Guideline Reference:
Spatial Representation: | One station, Mesquite Spring (in Death Valley National Park, near Scottys Castle), was sampled.
Temporal Representation: | Two samples were collected in 2002 and 2003.
Environmental Conditions: | The Mesquite Springs are within the Stovepipe Wells Hydrologic Subarea of the Amargosa Hydrologic Unit (HU No. 609.11). They supply drinking water to a campground. No site-specific water quality objectives apply to the springs. Chemical and radioactive constituents come from natural sources.
QAPP Information: | Data meet the quality assurance requirements of the SWAMP QAPP.
QAPP Information Reference(s):

DECISION ID | 23443 | Region 6
Mesquite Springs (Inyo County)

Pollutant: | Calcium
Final Listing Decision: | Do Not List on 303(d) list (TMDL required list)
Last Listing Cycle's Final Listing Decision: | Do Not List on 303(d) list (TMDL required list)(2010)
Revision Status | Original
Impairment from Pollutant or Pollution: | Pollutant
Regional Board Staff Conclusion: | This pollutant was considered for placement on the section 303(d) list in a previous assessment cycle. No new information was reviewed for this current assessment cycle. Therefore, the previous conclusion remains unchanged, and is as follows: This pollutant is being considered for placement on the section 303(d) list under section 3.2 of the Listing Policy. Under section 3.2 a single line of evidence is necessary to assess listing status. Two of evidence are available in the administrative record to assess this pollutant. There are no California or federal standards or water quality criteria for calcium. Based on the readily available data and information, the weight of evidence indicates that there is sufficient justification against placing this water segment-pollutant combination on the section 303(d) list in the Water Quality Limited Segments category. This conclusion is based on the staff findings that: 1. The data used satisfy the data quality requirements of section 6.1.4 of the Policy. 2. The data used satisfy the data quantity requirements of section 6.1.5 of the Policy. 3. There are no applicable standards or criteria and the data cannot be assessed pursuant to Table 3.2 of the Listing Policy. 4. Pursuant to section 3.11 of the Listing Policy, no additional data and information are available indicating that standards are not met.
Regional Board Staff Decision Recommendation: | No new data were assessed for this assessment cycle. The conclusion reached in the previous cycle remains in same. The Regional Board will update this decision when new data and information become available in a future assessment cycle.

Line of Evidence (LOE) for Decision ID 23443, Calcium | Region 6
Mesquite Springs (Inyo County)
LOE ID: | 21250
Pollutant: | Calcium
LOE Subgroup: | Pollutant-Water
Matrix: | Water
Fraction: | Dissolved
Beneficial Use: | Cold Freshwater Habitat
Number of Samples: | 2
Number of Exceedances: | 0
Data and Information Type: | Fixed station physical/chemical (conventional plus toxic pollutants)
Data Used to Assess Water Quality: | The U.S. Geological Survey sampled Mesquite Springs under the Region 6 SWAMP program in 2002 and 2003. The concentrations of dissolved calcium in two samples were 26.2 and 27.1 mg/L.
Data Reference: | 2007. SWAMP Data for the Amargosa Hydrologic Unit
SWAMP Data: | SWAMP
Water Quality Objective/Criterion: | There are no state or federal standards, water quality objectives or criteria for calcium.
Objective/Criterion Reference: | Water Quality Control Plan for the Lahontan Region (as amended)
Evaluation Guideline: |
Guideline Reference:
Spatial Representation: | One station, Mesquite Spring (in Death Valley National Park, near Scottys Castle), was sampled.
Temporal Representation: | Two samples were collected in 2002 and 2003.
Environmental Conditions: | The Mesquite Springs are within the Stovepipe Wells Hydrologic Subarea of the Amargosa Hydrologic Unit (HU No. 609.11). They supply drinking water to a campground. No site-specific water quality objectives apply to the springs. Chemical and radioactive constituents come from natural sources.
QAPP Information: | Data meet the quality assurance requirements of the SWAMP QAPP.
QAPP Information Reference(s):

DECISION ID | 23438 | Region 6
Mesquite Springs (Inyo County)

Pollutant: | Carbon 13/Carbon 12 ratio
Final Listing Decision: | Do Not List on 303(d) list (TMDL required list)
Last Listing Cycle's Final Listing Decision: | Do Not List on 303(d) list (TMDL required list)(2010)
Revision Status | Original
Impairment from Pollutant or Pollution: | Pollutant
Regional Board Staff Conclusion: | This pollutant was considered for placement on the section 303(d) list in a previous assessment cycle. No new information was reviewed for this current assessment cycle. Therefore, the previous conclusion remains unchanged, and is as follows: This pollutant is being considered for placement on the section 303(d) list under section 3.2 of the Listing Policy. Under section 3.2 a single line of evidence is necessary to assess listing status. Two lines of evidence are available in the administrative record to assess this pollutant. There are no California or federal criteria, standards, or water quality objectives applicable to carbon 13/carbon 12 ratio. Based on the readily available data and information, the weight of evidence indicates that there is sufficient justification against placing this water segment-pollutant combination on the section 303(d) list in the Water Quality Limited Segments category.
Regional Board Staff Decision Recommendation: | No new data were assessed for this assessment cycle. The conclusion reached in the previous cycle remains in same. The Regional Board will update this decision when new data and information become available in a future assessment cycle.

Line of Evidence (LOE) for Decision ID 23438, Carbon 13/Carbon 12 ratio | Region 6
Mesquite Springs (Inyo County)
LOE ID: | 21276
Pollutant: | Carbon 13/Carbon 12 ratio
LOE Subgroup: | Pollutant-Water
Matrix: | Water
Fraction: | Dissolved
Beneficial Use: | Cold Freshwater Habitat
Number of Samples: | 2
Number of Exceedances: | 0
Data and Information Type: | Fixed station physical/chemical (conventional plus toxic pollutants)
Data Used to Assess Water Quality: | The U.S. Geological Survey sampled Mesquite Springs under the Region 6 SWAMP program in 2002 and 2003. The reported carbon 13/carbon 12 ratios in two samples (as ml) were -6.15 and -6.19.
Data Reference: | 2007. SWAMP Data for the Amargosa Hydrologic Unit
SWAMP Data: | SWAMP
Water Quality Objective/Criterion: | There are no state or federal standards, water quality objectives or criteria for carbon 13/carbon 12 ratio.
Objective/Criterion Reference: | Water Quality Control Plan for the Lahontan Region (as amended)
Evaluation Guideline: |
Guideline Reference:
Spatial Representation: | One station, Mesquite Spring (in Death Valley National Park, near Scottys Castle), was sampled.
Temporal Representation: | Two samples were collected in 2002 and 2003.
Environmental Conditions: | The Mesquite Springs are within the Stovepipe Wells Hydrologic Subarea of the Amargosa Hydrologic Unit (HU No. 609.11). They supply drinking water to a campground. No site-specific water quality objectives apply to the springs. Chemical and radioactive constituents come from natural sources.
QAPP Information: | Data meet the quality assurance requirements of the SWAMP QAPP.
QAPP Information Reference(s):

DECISION ID | 28302 | Region 6
Mesquite Springs (Inyo County)

Pollutant: | Carbon 14
Final Listing Decision: | Do Not List on 303(d) list (TMDL required list)
Last Listing Cycle's Final Listing Decision: | Do Not List on 303(d) list (TMDL required list)(2010)
Revision Status | Original
Impairment from Pollutant or Pollution: | Pollutant
Regional Board Staff Conclusion: | This pollutant was considered for placement on the section 303(d) list in a previous assessment cycle. No new information was reviewed for this current assessment cycle. Therefore, the previous conclusion remains unchanged, and is as follows: This pollutant is being considered for placement on the section 303(d) list under section 3.1 of the Listing Policy. Under section 3.1 a single line of evidence is necessary to assess listing status. One line of evidence is available in the administrative record to assess this pollutant. There are no state or federal water quality standards or criteria for Carson 14, and no biological data are available for assessment of compliance with the narrative water quality objective for radioactivity. Based on the readily available data and information, the weight of evidence indicates that there is sufficient justification against placing this water segment-pollutant combination on the section 303(d) list in the Water Quality Limited Segments category. This conclusion is based on the staff findings that: 1. The data used satisfy the data quality requirements of section 6.1.4 of the Policy. 2. The data used do not satisfy the data quantity requirements of section 6.1.5 of the Policy. Only one sample per year is available. 3. No biological data are available for assessment of compliance with the narrative water quality objective.. 4. Pursuant to section 3.11 of the Listing Policy, no additional data and information are available indicating that standards are not met.
Regional Board Staff Decision Recommendation: | No new data were assessed for this assessment cycle. The conclusion reached in the previous cycle remains in same. The Regional Board will update this decision when new data and information become available in a future assessment cycle.

Line of Evidence (LOE) for Decision ID 28302, Carbon 14 | Region 6
Mesquite Springs (Inyo County)
LOE ID: | 21275
Pollutant: | Carbon 14
LOE Subgroup: | Pollutant-Water
Matrix: | Water
Fraction: | Dissolved
Beneficial Use: | Cold Freshwater Habitat
Number of Samples: | 2
Number of Exceedances: | 0
Data and Information Type: | Fixed station physical/chemical (conventional plus toxic pollutants)
Data Used to Assess Water Quality: | The U.S. Geological Survey sampled Mesquite Springs under the Region 6 SWAMP program in 2002 and 2003. Carbon 14 levels in two samples were 55.43 and 55.05 percent. The count errors (as a percentage) for these samples were 0.42 and 0.45 percent. No biological data are available for evaluation of bioaccumulation or effects on beneficial uses.
Data Reference: | 2007. SWAMP Data for the Amargosa Hydrologic Unit
SWAMP Data: | SWAMP
Water Quality Objective/Criterion: | There are no specific state or federal standards, water quality objectives or criteria for carbon 14. .The Lahontan Basin Plan's narrative water quality objective for "Radioactivity" states: "Radionuclides shall not be present in cocentrations which are deleterious to human, plant ,animal, or aquatic life nor which result in the accumulation of radionuclides in the food web to an extent which presents a hazard to human, plant or aquatic life." The objective also incorporates California Maximum Contaminant Level drinking water standards for radioactive constituents as water quality objectives for waters designated for the Municipal and Domestic Supply beneficial use.
Objective/Criterion Reference: | Water Quality Control Plan for the Lahontan Region (as amended)
Evaluation Guideline: |
Guideline Reference:
Spatial Representation: | One station, Mesquite Spring (in Death Valley National Park, near Scottys Castle), was sampled.
Temporal Representation: | Two samples were collected in 2002 and 2003.
Environmental Conditions: | The Mesquite Springs are within the Stovepipe Wells Hydrologic Subarea of the Amargosa Hydrologic Unit (HU No. 609.11). They supply drinking water to a campground. No site-specific water quality objectives apply to the springs. Chemical and radioactive constituents come from natural sources.
QAPP Information: | Data meet the quality assurance requirements of the SWAMP QAPP.
QAPP Information Reference(s):

DECISION ID | 23264 | Region 6
Mesquite Springs (Inyo County)

Pollutant: | Chloride
Final Listing Decision: | Do Not List on 303(d) list (TMDL required list)
Last Listing Cycle's Final Listing Decision: | Do Not List on 303(d) list (TMDL required list)(2010)
Revision Status | Original
Impairment from Pollutant or Pollution: | Pollutant
Regional Board Staff Conclusion: | This pollutant was considered for placement on the section 303(d) list in a previous assessment cycle. No new information was reviewed for this current assessment cycle. Therefore, the previous conclusion remains unchanged, and is as follows: This pollutant is being considered for placement on the section 303(d) list under section 3.2 of the Listing Policy. Under section 3.2 a single line of evidence is necessary to assess listing status. Two lines of evidence are available in the administrative record to assess this pollutant. Neither of the samples exceeds the applicable criterion and water quality objective. Based on the readily available data and information, the weight of evidence indicates that there is sufficient justification against placing this water segment-pollutant combination on the section 303(d) list in the Water Quality Limited Segments category. This conclusion is based on the staff findings that: 1. The data used satisfy the data quality requirements of section 6.1.4 of the Policy. 2. The data used do not satisfy the data quantity requirements of section 6.1.5 of the Policy in that only one sample per year is available. 3. Neither of two samples exceeded the applicable standards. However, the minimum sample number requirements of Table 3.2 of the Listing Policy were not met. 4. Pursuant to section 3.11 of the Listing Policy, no additional data and information are available indicating that standards are not met.
Regional Board Staff Decision Recommendation: | No new data were assessed for this assessment cycle. The conclusion reached in the previous cycle remains in same. The Regional Board will update this decision when new data and information become available in a future assessment cycle.

Line of Evidence (LOE) for Decision ID 23264, Chloride | Region 6
Mesquite Springs (Inyo County)
LOE ID: | 5745
Pollutant: | Chloride
LOE Subgroup: | Pollutant-Water
Matrix: | Water
Fraction: | Dissolved
Beneficial Use: | Cold Freshwater Habitat
Number of Samples: | 2
Number of Exceedances: | 0
Data and Information Type: | Not Specified
Data Used to Assess Water Quality: | The U.S. Geological Survey sampled Mesquite Springs under the Region 6 SWAMP program. Chloride concentrations in two samples were 84.6 and 82.6 mg/L. The USEPA criterion was not exceeded, but sample numbers were too small for use with the Listing Policy's binomial model.
Data Reference: | 2007. SWAMP Data for the Amargosa Hydrologic Unit
SWAMP Data: | SWAMP
Water Quality Objective/Criterion: | The U.S. Environmental Protection Agency's (USEPA's) 4 day average freshwater aquatic life criterion is 230 mg/L
Objective/Criterion Reference: | National recommended water quality criteria: 2002. EPA-822-R-02-047 Washington, D.C. USEPA
Evaluation Guideline: |
Guideline Reference:
Spatial Representation: | One station, Mesquite Spring (in Death Valley National Park, near Scottys Castle), was sampled.
Temporal Representation: | Two samples were collected in 2002 and 2003.
Environmental Conditions: | The Mesquite Springs are within the Stovepipe Wells Hydrologic Subarea of the Amargosa Hydrologic Unit (HU No. 609.11). They supply drinking water to a campground. No site-specific water quality objectives apply to the springs. Chemical and radioactive constituents, including salts, come from natural sources.
QAPP Information: | Data meet the quality assurance requirements of the SWAMP QAPP.
QAPP Information Reference(s):
Line of Evidence (LOE) for Decision ID 23264, Chloride | Region 6
Mesquite Springs (Inyo County)
LOE ID: | 5234
Pollutant: | Chloride
LOE Subgroup: | Pollutant-Water
Matrix: | Water
Fraction: | Dissolved
Beneficial Use: | Municipal & Domestic Supply
Number of Samples: | 2
Number of Exceedances: | 0
Data and Information Type: | Not Specified
Data Used to Assess Water Quality: | The U.S. Geological Survey sampled Mesquite Springs under the Region 6 SWAMP program. Chloride concentrations in two samples were 84.6 and 82.6 mg/L. The MCL was not exceeded, but sample numbers were too small for use with the Listing Policy's binomial model.
Data Reference: | 2007. SWAMP Data for the Amargosa Hydrologic Unit
SWAMP Data: | SWAMP
Water Quality Objective/Criterion: | California Maximum Contaminant Levels (MCLs) apply to ambient waters under the Lahontan Basin Plan's "Chemical Constituents" objective. The MCL for chloride is 250 mg/L.
Objective/Criterion Reference: | Water Quality Control Plan for the Lahontan Region (as amended)
Evaluation Guideline: |
Guideline Reference:
Spatial Representation: | One station, Mesquite Spring (in Death Valley National Park, near Scottys Castle), was sampled.
Temporal Representation: | Two samples were collected in 2002 and 2003.
Environmental Conditions: | The Mesquite Springs are within the Stovepipe Wells Hydrologic Subarea of the Amargosa Hydrologic Unit (HU No. 609.11). They supply drinking water to a campground. No site-specific water quality objectives apply to the springs. Chemical and radioactive constituents, including salts, come from natural sources.
QAPP Information: | Data meet the quality assurance requirements of the SWAMP QAPP.
QAPP Information Reference(s):

DECISION ID | 20750 | Region 6
Mesquite Springs (Inyo County)

Pollutant: | Chromium (total)
Final Listing Decision: | Do Not List on 303(d) list (TMDL required list)
Last Listing Cycle's Final Listing Decision: | Do Not List on 303(d) list (TMDL required list)(2010)
Revision Status | Original
Impairment from Pollutant or Pollution: | Pollutant
Regional Board Staff Conclusion: | This pollutant was considered for placement on the section 303(d) list in a previous assessment cycle. No new information was reviewed for this current assessment cycle. Therefore, the previous conclusion remains unchanged, and is as follows: This pollutant is being considered for placement on the section 303(d) list under section 3.1 of the Listing Policy. Under section 3.1 a single line of evidence is necessary to assess listing status. Two lines of evidence are available in the administrative record to assess this pollutant. None of the samples exceed the applicable water quality objectives. Based on the readily available data and information, the weight of evidence indicates that there is sufficient justification against placing this water segment-pollutant combination on the section 303(d) list in the Water Quality Limited Segments category. This conclusion is based on the staff findings that: 1. The data used satisfy the data quality requirements of section 6.1.4 of the Policy. 2. The data used do not satisfy the data quantity requirements of section 6.1.5 of the Policy in that only one sample per year is available. 3. None of two samples exceeded the applicable objectives and this does not exceed the allowable frequency listed in Table 3.1 of the Listing Policy. 4. Pursuant to section 3.11 of the Listing Policy, no additional data and information are available indicating that standards are not met.
Regional Board Staff Decision Recommendation: | No new data were assessed for this assessment cycle. The conclusion reached in the previous cycle remains in same. The Regional Board will update this decision when new data and information become available in a future assessment cycle.

Line of Evidence (LOE) for Decision ID 20750, Chromium (total) | Region 6
Mesquite Springs (Inyo County)
LOE ID: | 5309
Pollutant: | Chromium (total)
LOE Subgroup: | Pollutant-Water
Matrix: | Water
Fraction: | Dissolved
Beneficial Use: | Municipal & Domestic Supply
Number of Samples: | 2
Number of Exceedances: | 0
Data and Information Type: | Fixed station physical/chemical (conventional plus toxic pollutants)
Data Used to Assess Water Quality: | The U.S. Geological Survey sampled Mesquite Springs under the Region 6 SWAMP program. Dissolved chromium concentrations in two samples were 0.8 and 1 ug/L. The MCL was not exceeded. (The SWAMP data do not distinguish between hexavalent and trivalent chromium. MCLs for metals are expressed as total rather than dissolved, but only dissolved chromium data are available for this station.)
Data Reference: | 2007. SWAMP Data for the Amargosa Hydrologic Unit
SWAMP Data: | SWAMP
Water Quality Objective/Criterion: | California Maximum Contaminant Levels (MCLs) apply to ambient waters under the Lahontan Basin Plan's "Chemical Constituents" objective. The California MCL for chromium is 50 ug/L (as total chromium)..
Objective/Criterion Reference: | Water Quality Control Plan for the Lahontan Region (as amended)
Evaluation Guideline: |
Guideline Reference:
Spatial Representation: | One station, Mesquite Spring (in Death Valley National Park, near Scottys Castle), was sampled.
Temporal Representation: | Two samples were collected in 2002 and 2003.
Environmental Conditions: | The Mesquite Springs are within the Stovepipe Wells Hydrologic Subarea of the Amargosa Hydrologic Unit (HU No. 609.11). They supply drinking water to a campground. No site-specific water quality objectives apply to the springs. Chemical and radioactive constituents come from natural sources.
QAPP Information: | Data meet the quality assurance requirements of the SWAMP QAPP.
QAPP Information Reference(s):
Line of Evidence (LOE) for Decision ID 20750, Chromium (total) | Region 6
Mesquite Springs (Inyo County)
LOE ID: | 5310
Pollutant: | Chromium (total)
LOE Subgroup: | Pollutant-Water
Matrix: | Water
Fraction: | Dissolved
Beneficial Use: | Cold Freshwater Habitat
Number of Samples: | 2
Number of Exceedances: | 0
Data and Information Type: | Fixed station physical/chemical (conventional plus toxic pollutants)
Data Used to Assess Water Quality: | The U.S. Geological Survey sampled Mesquite Springs under the Region 6 SWAMP program. Dissolved chromium concentrations in two samples were 0.8 and 10 ug/L. The CTR standards were not exceeded. (The SWAMP data do not distinguish between trivalent and hexavalent chromium. Only data for dissolved chromium were available.)
Data Reference: | 2007. SWAMP Data for the Amargosa Hydrologic Unit
SWAMP Data: | SWAMP
Water Quality Objective/Criterion: | The California Toxics Rule (CTR) standard for Chromium III, for protection of freshwater aquatic life, is dependent on hardness. At the hardness levels reported for this station the acute toxicity standard ranges from 650.12 to 663.08 ug/L. The chronic toxicity standard ranges from 210.89 to 215.10 ug/L.
Objective/Criterion Reference: | Water Quality Standards 2000. Establishment of numeric criteria for priority toxic pollutants for the State of California: Rules and regulations. Federal Register Vol. 65, No. 97. Washington, D.C.: Environmental Protection Agency
Evaluation Guideline: |
Guideline Reference:
Spatial Representation: | One station, Mesquite Spring (in Death Valley National Park, near Scottys Castle), was sampled.
Temporal Representation: | Two samples were collected in 2002 and 2003.
Environmental Conditions: | The Mesquite Springs are within the Stovepipe Wells Hydrologic Subarea of the Amargosa Hydrologic Unit (HU No. 609.11). They supply drinking water to a campground. No site-specific water quality objectives apply to the springs. Chemical and radioactive constituents come from natural sources.
QAPP Information: | Data meet the quality assurance requirements of the SWAMP QAPP.
QAPP Information Reference(s):

DECISION ID | 21267 | Region 6
Mesquite Springs (Inyo County)

Pollutant: | Cobalt
Final Listing Decision: | Do Not List on 303(d) list (TMDL required list)
Last Listing Cycle's Final Listing Decision: | Do Not List on 303(d) list (TMDL required list)(2010)
Revision Status | Original
Impairment from Pollutant or Pollution: | Pollutant
Regional Board Staff Conclusion: | This pollutant was considered for placement on the section 303(d) list in a previous assessment cycle. No new information was reviewed for this current assessment cycle. Therefore, the previous conclusion remains unchanged, and is as follows: This pollutant is being considered for placement on the section 303(d) list under section 3.1 of the Listing Policy. Under section 3.1 a single line of evidence is necessary to assess listing status. Two lines of evidence are available in the administrative record to assess this pollutant. There are no California or federal criteria, standards, or water quality objectives applicable to cobalt. Based on the readily available data and information, the weight of evidence indicates that there is sufficient justification against placing this water segment-pollutant combination on the section 303(d) list in the Water Quality Limited Segments category.
Regional Board Staff Decision Recommendation: | No new data were assessed for this assessment cycle. The conclusion reached in the previous cycle remains in same. The Regional Board will update this decision when new data and information become available in a future assessment cycle.

Line of Evidence (LOE) for Decision ID 21267, Cobalt | Region 6
Mesquite Springs (Inyo County)
LOE ID: | 6040
Pollutant: | Cobalt
LOE Subgroup: | Pollutant-Water
Matrix: | Water
Fraction: | Dissolved
Beneficial Use: | Municipal & Domestic Supply
Number of Samples: | 2
Number of Exceedances: | 0
Data and Information Type: | Fixed station physical/chemical (conventional plus toxic pollutants)
Data Used to Assess Water Quality: | The U.S. Geological Survey sampled Mesquite Springs under the Region 6 SWAMP program in 2002 and 2003. The concentrations of dissolved cobalt in two samples were 0.053 and 0.06 ug/L.
Data Reference: | 2007. SWAMP Data for the Amargosa Hydrologic Unit
SWAMP Data: | SWAMP
Water Quality Objective/Criterion: | There are no state or federal standards, water quality objectives or criteria for cobalt.
Objective/Criterion Reference: | Water Quality Control Plan for the Lahontan Region (as amended)
Evaluation Guideline: |
Guideline Reference:
Spatial Representation: | One station, Mesquite Spring (in Death Valley National Park, near Scottys Castle), was sampled.
Temporal Representation: | Two samples were collected in 2002 and 2003.
Environmental Conditions: | The Mesquite Springs are within the Stovepipe Wells Hydrologic Subarea of the Amargosa Hydrologic Unit (HU No. 609.11). They supply drinking water to a campground. No site-specific water quality objectives apply to the springs. Chemical and radioactive constituents come from natural sources.
QAPP Information: | Data meet the quality assurance requirements of the SWAMP QAPP.
QAPP Information Reference(s):
Line of Evidence (LOE) for Decision ID 21267, Cobalt | Region 6
Mesquite Springs (Inyo County)
LOE ID: | 6043
Pollutant: | Cobalt
LOE Subgroup: | Pollutant-Water
Matrix: | Water
Fraction: | Dissolved
Beneficial Use: | Cold Freshwater Habitat
Number of Samples: | 2
Number of Exceedances: | 0
Data and Information Type: | Fixed station physical/chemical (conventional plus toxic pollutants)
Data Used to Assess Water Quality: | The U.S. Geological Survey sampled Mesquite Springs under the Region 6 SWAMP program in 2002 and 2003. The concentrations of dissolved cobalt in two samples were 0.053 and 0.06 ug/L.
Data Reference: | 2007. SWAMP Data for the Amargosa Hydrologic Unit
SWAMP Data: | SWAMP
Water Quality Objective/Criterion: | There are no state or federal standards, water quality objectives or criteria for cobalt.
Objective/Criterion Reference: | Water Quality Control Plan for the Lahontan Region (as amended)
Evaluation Guideline: |
Guideline Reference:
Spatial Representation: | One station, Mesquite Spring (in Death Valley National Park, near Scottys Castle), was sampled.
Temporal Representation: | Two samples were collected in 2002 and 2003.
Environmental Conditions: | The Mesquite Springs are within the Stovepipe Wells Hydrologic Subarea of the Amargosa Hydrologic Unit (HU No. 609.11). They supply drinking water to a campground. No site-specific water quality objectives apply to the springs. Chemical and radioactive constituents come from natural sources.
QAPP Information: | Data meet the quality assurance requirements of the SWAMP QAPP.
QAPP Information Reference(s):

DECISION ID | 20879 | Region 6
Mesquite Springs (Inyo County)

Pollutant: | Copper
Final Listing Decision: | Do Not List on 303(d) list (TMDL required list)
Last Listing Cycle's Final Listing Decision: | Do Not List on 303(d) list (TMDL required list)(2010)
Revision Status | Original
Impairment from Pollutant or Pollution: | Pollutant
Regional Board Staff Conclusion: | This pollutant was considered for placement on the section 303(d) list in a previous assessment cycle. No new information was reviewed for this current assessment cycle. Therefore, the previous conclusion remains unchanged, and is as follows: This pollutant is being considered for placement on the section 303(d) list under section 3.1 of the Listing Policy. Under section 3.1 a single line of evidence is necessary to assess listing status. Two lines of evidence are available in the administrative record to assess this pollutant. Neither of the samples exceeds the applicable standards. Based on the readily available data and information, the weight of evidence indicates that there is sufficient justification against placing this water segment-pollutant combination on the section 303(d) list in the Water Quality Limited Segments category. This conclusion is based on the staff findings that: 1. The data used satisfy the data quality requirements of section 6.1.4 of the Policy. 2. The data used do not satisfy the data quantity requirements of section 6.1.5 of the Policy in that only one sample per year is available. 3. Neither of two samples exceeded the applicable water quality standards and this does not exceed the allowable frequency listed in Table 3.1 of the Listing Policy. 4. Pursuant to section 3.11 of the Listing Policy, no additional data and information are available indicating that standards are not met.
Regional Board Staff Decision Recommendation: | No new data were assessed for this assessment cycle. The conclusion reached in the previous cycle remains in same. The Regional Board will update this decision when new data and information become available in a future assessment cycle.

Line of Evidence (LOE) for Decision ID 20879, Copper | Region 6
Mesquite Springs (Inyo County)
LOE ID: | 5743
Pollutant: | Copper
LOE Subgroup: | Pollutant-Water
Matrix: | Water
Fraction: | Dissolved
Beneficial Use: | Cold Freshwater Habitat
Number of Samples: | 2
Number of Exceedances: | 0
Data and Information Type: | Fixed station physical/chemical (conventional plus toxic pollutants)
Data Used to Assess Water Quality: | The U.S. Geological Survey sampled Mesquite Springs under the Region 6 SWAMP program in 2002 and 2003. Dissolved copper concentrations in two samples were 0.9 and 0.7 ug/L. The California Toxics Rule standards were not exceeded.
Data Reference: | 2007. SWAMP Data for the Amargosa Hydrologic Unit
SWAMP Data: | SWAMP
Water Quality Objective/Criterion: | The California Toxics Rule copper standard for protection of freshwater aquatic life is dependent on hardness. At the reported hardness levels, the acute toxicity standard ranges from 16.33 to 16.71 ug/L. The chronic toxicity standard ranges from 10.69 to 10.91 ug/L.
Objective/Criterion Reference: | Water Quality Standards 2000. Establishment of numeric criteria for priority toxic pollutants for the State of California: Rules and regulations. Federal Register Vol. 65, No. 97. Washington, D.C.: Environmental Protection Agency
Evaluation Guideline: |
Guideline Reference:
Spatial Representation: | One station, Mesquite Spring (in Death Valley National Park, near Scottys Castle), was sampled.
Temporal Representation: | Two samples were collected in 2002 and 2003.
Environmental Conditions: | The Mesquite Springs are within the Stovepipe Wells Hydrologic Subarea of the Amargosa Hydrologic Unit (HU No. 609.11). They supply drinking water to a campground. No site-specific water quality objectives apply to the springs. Chemical and radioactive constituents come from natural sources.
QAPP Information: | Data meet the quality assurance requirements of the SWAMP QAPP.
QAPP Information Reference(s):
Line of Evidence (LOE) for Decision ID 20879, Copper | Region 6
Mesquite Springs (Inyo County)
LOE ID: | 5311
Pollutant: | Copper
LOE Subgroup: | Pollutant-Water
Matrix: | Water
Fraction: | Dissolved
Beneficial Use: | Municipal & Domestic Supply
Number of Samples: | 2
Number of Exceedances: | 0
Data and Information Type: | Fixed station physical/chemical (conventional plus toxic pollutants)
Data Used to Assess Water Quality: | The U.S. Geological Survey sampled Mesquite Springs under the Region 6 SWAMP program in 2002 and 2003. Dissolved copper concentrations in two samples were 0.9 and 0.7 ug/L. The MCLs were not exceeded. (Note: MCLs for metals are expressed as total rather than dissolved.)
Data Reference: | 2007. SWAMP Data for the Amargosa Hydrologic Unit
SWAMP Data: | SWAMP
Water Quality Objective/Criterion: | California Maximum Contaminant Levels (MCLs) apply to ambient waters under the Lahontan Basin Plan's "Chemical Constituents" objective. The primary MCL for copper is 1300 ug/L; the secondary MCL is 1000 ug/L.
Objective/Criterion Reference: | Water Quality Control Plan for the Lahontan Region (as amended)
Evaluation Guideline: |
Guideline Reference:
Spatial Representation: | One station, Mesquite Spring (in Death Valley National Park, near Scottys Castle), was sampled.
Temporal Representation: | Two samples were collected in 2002 and 2003.
Environmental Conditions: | The Mesquite Springs are within the Stovepipe Wells Hydrologic Subarea of the Amargosa Hydrologic Unit (HU No. 609.11). They supply drinking water to a campground. No site-specific water quality objectives apply to the springs. Chemical and radioactive constituents come from natural sources.
QAPP Information: | Data meet the quality assurance requirements of the SWAMP QAPP.
QAPP Information Reference(s):

DECISION ID | 23182 | Region 6
Mesquite Springs (Inyo County)

Pollutant: | Deuterium/Protium ratio
Final Listing Decision: | Do Not List on 303(d) list (TMDL required list)
Last Listing Cycle's Final Listing Decision: | Do Not List on 303(d) list (TMDL required list)(2010)
Revision Status | Original
Impairment from Pollutant or Pollution: | Pollutant
Regional Board Staff Conclusion: | This pollutant was considered for placement on the section 303(d) list in a previous assessment cycle. No new information was reviewed for this current assessment cycle. Therefore, the previous conclusion remains unchanged, and is as follows: This pollutant is being considered for placement on the section 303(d) list under section 3.2 of the Listing Policy. Under section 3.2 a single line of evidence is necessary to assess listing status. Two lines of evidence are available in the administrative record to assess this pollutant. There are no California or federal criteria, standards, or water quality objectives applicable to deuterium/protium ratio. Based on the readily available data and information, the weight of evidence indicates that there is sufficient justification against placing this water segment-pollutant combination on the section 303(d) list in the Water Quality Limited Segments category.
Regional Board Staff Decision Recommendation: | No new data were assessed for this assessment cycle. The conclusion reached in the previous cycle remains in same. The Regional Board will update this decision when new data and information become available in a future assessment cycle.

Line of Evidence (LOE) for Decision ID 23182, Deuterium/Protium ratio | Region 6
Mesquite Springs (Inyo County)
LOE ID: | 21283
Pollutant: | Deuterium/Protium ratio
LOE Subgroup: | Pollutant-Water
Matrix: | Water
Fraction: | Dissolved
Beneficial Use: | Cold Freshwater Habitat
Number of Samples: | 2
Number of Exceedances: | 0
Data and Information Type: | Fixed station physical/chemical (conventional plus toxic pollutants)
Data Used to Assess Water Quality: | The U.S. Geological Survey sampled Mesquite Springs under the Region 6 SWAMP program in 2002 and 2003. The reported deuterium/protium ratios in two samples (as ml) were -108 and -108.
Data Reference: | 2007. SWAMP Data for the Amargosa Hydrologic Unit
SWAMP Data: | SWAMP
Water Quality Objective/Criterion: | There are no state or federal standards, water quality objectives or criteria for deuterium/protium ratio.
Objective/Criterion Reference: | Water Quality Control Plan for the Lahontan Region (as amended)
Evaluation Guideline: |
Guideline Reference:
Spatial Representation: | One station, Mesquite Spring (in Death Valley National Park, near Scottys Castle), was sampled.
Temporal Representation: | Two samples were collected in 2002 and 2003.
Environmental Conditions: | The Mesquite Springs are within the Stovepipe Wells Hydrologic Subarea of the Amargosa Hydrologic Unit (HU No. 609.11). They supply drinking water to a campground. No site-specific water quality objectives apply to the springs. Chemical and radioactive constituents come from natural sources.
QAPP Information: | Data meet the quality assurance requirements of the SWAMP QAPP.
QAPP Information Reference(s):

DECISION ID | 23265 | Region 6
Mesquite Springs (Inyo County)

Pollutant: | Fecal Coliform
Final Listing Decision: | Do Not List on 303(d) list (TMDL required list)
Last Listing Cycle's Final Listing Decision: | Do Not List on 303(d) list (TMDL required list)(2010)
Revision Status | Original
Impairment from Pollutant or Pollution: | Pollutant
Regional Board Staff Conclusion: | This pollutant was considered for placement on the section 303(d) list in a previous assessment cycle. No new information was reviewed for this current assessment cycle. Therefore, the previous conclusion remains unchanged, and is as follows: This pollutant is being considered for placement on the section 303(d) list under section 3.3 of the Listing Policy. Under section 3.3 a single line of evidence is necessary to assess listing status. Two lines of evidence are available in the administrative record to assess this pollutant. Neither of the samples exceeds the water quality objective. Based on the readily available data and information, the weight of evidence indicates that there is sufficient justification against placing this water segment-pollutant combination on the section 303(d) list in the Water Quality Limited Segments category. This conclusion is based on the staff findings that: 1. The data used satisfy the data quality requirements of section 6.1.4 of the Policy. 2. The data used do not satisfy the data quantity requirements of section 6.1.5 of the Policy in that only one sample per year is available. 3. Neither of two samples exceeded the water quality objective and this does not exceed the allowable frequency listed in Table 3.2 of the Listing Policy. However, the minimum sample number requirements of Table 3.2 were not met. 4. Pursuant to section 3.11 of the Listing Policy, no additional data and information are available indicating that standards are not met.
Regional Board Staff Decision Recommendation: | No new data were assessed for this assessment cycle. The conclusion reached in the previous cycle remains in same. The Regional Board will update this decision when new data and information become available in a future assessment cycle.

Line of Evidence (LOE) for Decision ID 23265, Fecal Coliform | Region 6
Mesquite Springs (Inyo County)
LOE ID: | 5710
Pollutant: | Fecal Coliform
LOE Subgroup: | Pollutant-Water
Matrix: | Water
Fraction: | None
Beneficial Use: | Water Contact Recreation
Number of Samples: | 2
Number of Exceedances: | 0
Data and Information Type: | Water column surveys (e.g. fecal coliform)
Data Used to Assess Water Quality: | The U.S. Geological Survey sampled Mesquite Springs once a year in 2002 and 2003 under the Region 6 SWAMP program. Fecal coliform counts in two samples were below the detection level. Per Listing Policy Section 6.1.5.5, the objective is presumed to be attained.
Data Reference: | 2007. SWAMP Data for the Amargosa Hydrologic Unit
SWAMP Data: | SWAMP
Water Quality Objective/Criterion: | The Lahontan Basin Plan's objective for coliform bacteria states: "Waters shall not contain concentrations of coliform organisms attributable to anthropogenic sources, including human and livestock wastes. The fecal coliform concentration during any 30-day period shall not exceed a log mean of 20/100 ml, nor shall more than 10 percent of all samples collected during any 30-day period exceed 40/100 ml. The log mean shall ideally be based on a minimum of not less than five samples collected as evenly spaced as practicable during any 30-day period. However, a log mean concentration exceeding 20/100 ml for any 30-day period shall indicate violation of this objective even if fewer than five samples were collected."
Objective/Criterion Reference: | Water Quality Control Plan for the Lahontan Region (as amended)
Evaluation Guideline: |
Guideline Reference:
Spatial Representation: | One station, Mesquite Spring (Death Valley National Park), near Scottys Castle, was sampled.
Temporal Representation: | Two samples were collected in 2002 and 2003.
Environmental Conditions: | The Mesquite Springs are within the Stovepipe Wells Hydrologic Subarea of the Amargosa Hydrologic Unit (HU No. 609.11). They supply drinking water to a campground. No site-specific water quality objectives apply to the springs.
QAPP Information: | Data meet the quality assurance requirements of the SWAMP QAPP.
QAPP Information Reference(s):
Line of Evidence (LOE) for Decision ID 23265, Fecal Coliform | Region 6
Mesquite Springs (Inyo County)
LOE ID: | 5709
Pollutant: | Fecal Coliform
LOE Subgroup: | Pollutant-Water
Matrix: | Water
Fraction: | None
Beneficial Use: | Municipal & Domestic Supply
Number of Samples: | 2
Number of Exceedances: | 0
Data and Information Type: | Water column surveys (e.g. fecal coliform)
Data Used to Assess Water Quality: | The U.S. Geological Survey sampled Mesquite Springs once a year in 2002 and 2003 under the Region 6 SWAMP program. Fecal coliform counts in two samples were below the detection level. Per Listing Policy Section 6.1.5.5, the objective is presumed to be attained.
Data Reference: | 2007. SWAMP Data for the Amargosa Hydrologic Unit
SWAMP Data: | SWAMP
Water Quality Objective/Criterion: | The Lahontan Basin Plan's objective for coliform bacteria states: "Waters shall not contain concentrations of coliform organisms attributable to anthropogenic sources, including human and livestock wastes. The fecal coliform concentration during any 30-day period shall not exceed a log mean of 20/100 ml, nor shall more than 10 percent of all samples collected during any 30-day period exceed 40/100 ml. The log mean shall ideally be based on a minimum of not less than five samples collected as evenly spaced as practicable during any 30-day period. However, a log mean concentration exceeding 20/100 ml for any 30-day period shall indicate violation of this objective even if fewer than five samples were collected."
Objective/Criterion Reference: | Water Quality Control Plan for the Lahontan Region (as amended)
Evaluation Guideline: |
Guideline Reference:
Spatial Representation: | One station, Mesquite Spring (Death Valley National Park), near Scottys Castle, was sampled.
Temporal Representation: | Two samples were collected in 2002 and 2003.
Environmental Conditions: | The Mesquite Springs are within the Stovepipe Wells Hydrologic Subarea of the Amargosa Hydrologic Unit (HU No. 609.11). They supply drinking water to a campground. No site-specific water quality objectives apply to the springs.
QAPP Information: | Data meet the quality assurance requirements of the SWAMP QAPP.
QAPP Information Reference(s):

DECISION ID | 23186 | Region 6
Mesquite Springs (Inyo County)

Pollutant: | Fluoride
Final Listing Decision: | Do Not List on 303(d) list (TMDL required list)
Last Listing Cycle's Final Listing Decision: | Do Not List on 303(d) list (TMDL required list)(2010)
Revision Status | Original
Impairment from Pollutant or Pollution: | Pollutant
Regional Board Staff Conclusion: | This pollutant was considered for placement on the section 303(d) list in a previous assessment cycle. No new information was reviewed for this current assessment cycle. Therefore, the previous conclusion remains unchanged, and is as follows: This pollutant is being considered for placement on the section 303(d) list under section 3.2 of the Listing Policy. Under section 3.2 a single line of evidence is necessary to assess listing status. One line of evidence is available in the administrative record to assess this pollutant. Two of the samples exceed the water quality objective. Based on the readily available data and information, the weight of evidence indicates that there is sufficient justification against placing this water segment-pollutant combination on the section 303(d) list in the Water Quality Limited Segments category. This conclusion is based on the staff findings that: 1. The data used satisfy the data quality requirements of section 6.1.4 of the Policy. 2. The data used do not satisfy the data quantity requirements of section 6.1.5 of the Policy in that only one sample per year is available. 3. Two of two samples exceeded the California Maximum Contaminant Level and this does not exceed the allowable frequency listed in Table 3.2 of the Listing Policy. However, the minimum sample number requirements of the policy were not met. 4. Pursuant to section 3.11 of the Listing Policy, no additional data and information are available indicating that standards are not met.
Regional Board Staff Decision Recommendation: | No new data were assessed for this assessment cycle. The conclusion reached in the previous cycle remains in same. The Regional Board will update this decision when new data and information become available in a future assessment cycle.

Line of Evidence (LOE) for Decision ID 23186, Fluoride | Region 6
Mesquite Springs (Inyo County)
LOE ID: | 5238
Pollutant: | Fluoride
LOE Subgroup: | Pollutant-Water
Matrix: | Water
Fraction: | Dissolved
Beneficial Use: | Municipal & Domestic Supply
Number of Samples: | 2
Number of Exceedances: | 2
Data and Information Type: | Not Specified
Data Used to Assess Water Quality: | The U.S. Geological Survey sampled Mesquite Springs under the Region 6 SWAMP program. Fluoride concentrations in two samples were 3.74 and 3.46 mg/L.. The MCL was exceeded.
Data Reference: | 2007. SWAMP Data for the Amargosa Hydrologic Unit
SWAMP Data: | SWAMP
Water Quality Objective/Criterion: | California Maximum Contaminant Levels (MCLs) apply to ambient waters under the Lahontan Basin Plan's "Chemical Constituents" objective. The MCL for fluoride is 2 mg/L.
Objective/Criterion Reference: | Water Quality Control Plan for the Lahontan Region (as amended)
Evaluation Guideline: |
Guideline Reference:
Spatial Representation: | One station, Mesquite Spring (in Death Valley National Park, near Scottys Castle), was sampled.
Temporal Representation: | Two samples were collected in 2002 and 2003.
Environmental Conditions: | The Mesquite Springs are within the Stovepipe Wells Hydrologic Subarea of the Amargosa Hydrologic Unit (HU No. 609.11). They supply drinking water to a campground. No site-specific water quality objectives apply to the springs. Chemical and radioactive constituents come from natural sources.
QAPP Information: | Data meet the quality assurance requirements of the SWAMP QAPP.
QAPP Information Reference(s):

DECISION ID | 23225 | Region 6
Mesquite Springs (Inyo County)

Pollutant: | Hardness
Final Listing Decision: | Do Not List on 303(d) list (TMDL required list)
Last Listing Cycle's Final Listing Decision: | Do Not List on 303(d) list (TMDL required list)(2010)
Revision Status | Original
Impairment from Pollutant or Pollution: | Pollutant
Regional Board Staff Conclusion: | This pollutant was considered for placement on the section 303(d) list in a previous assessment cycle. No new information was reviewed for this current assessment cycle. Therefore, the previous conclusion remains unchanged, and is as follows: This pollutant is being considered for placement on the section 303(d) list under section 3.2 of the Listing Policy. Under section 3.2 a single line of evidence is necessary to assess listing status. One line of evidence is available in the administrative record to assess this pollutant. There are no applicable state or federal standards or criteria for hardness. Based on the readily available data and information, the weight of evidence indicates that there is sufficient justification against placing this water segment-pollutant combination on the section 303(d) list in the Water Quality Limited Segments category. This conclusion is based on the staff findings that: 1. The data used satisfy the data quality requirements of section 6.1.4 of the Policy. 2. The data used do not satisfy the data quantity requirements of section 6.1.5 of the Policy. 3. There are no applicable water quality standards or criteria. 4. Pursuant to section 3.11 of the Listing Policy, no additional data and information are available indicating that standards are not met.
Regional Board Staff Decision Recommendation: | No new data were assessed for this assessment cycle. The conclusion reached in the previous cycle remains in same. The Regional Board will update this decision when new data and information become available in a future assessment cycle.

Line of Evidence (LOE) for Decision ID 23225, Hardness | Region 6
Mesquite Springs (Inyo County)
LOE ID: | 21252
Pollutant: | Hardness
LOE Subgroup: | Pollutant-Water
Matrix: | Water
Fraction: | Dissolved
Beneficial Use: | Cold Freshwater Habitat
Number of Samples: | 2
Number of Exceedances: | 0
Data and Information Type: | Fixed station physical/chemical (conventional plus toxic pollutants)
Data Used to Assess Water Quality: | The U.S. Geological Survey sampled Mesquite Springs under the Region 6 SWAMP program in 2002 and 2003. Two samples had calculated hardness values of 123 and 126 mg/L.
Data Reference: | 2007. SWAMP Data for the Amargosa Hydrologic Unit
SWAMP Data: | SWAMP
Water Quality Objective/Criterion: | There are no state or federal standards or criteria for hardness. Hardness is monitored for purposes such as determination of the applicable criteria and standards for metals whose toxicity is hardness-dependent. The U.S. Environmental Protection Agency's 1986 "Gold Book" includes generally accepted categories of hardness. Calcium and magnesium are the major ions contributing to hardness, and hardness is generally expressed as calcium carbonate. Water with a hardness of 0 to 75 mg equivalent CaCO3/L is considered "soft."
Objective/Criterion Reference: | Water Quality Control Plan for the Lahontan Region (as amended)
Evaluation Guideline: |
Guideline Reference:
Spatial Representation: | One station, Mesquite Spring (in Death Valley National Park, near Scottys Castle), was sampled.
Temporal Representation: | Hardness was calculated for two samples collected in 2002 and 2003.
Environmental Conditions: | The Mesquite Springs are within the Stovepipe Wells Hydrologic Subarea of the Amargosa Hydrologic Unit (HU No. 609.11). They supply drinking water to a campground. No site-specific water quality objectives apply to the springs. Chemical and radioactive constituents come from natural sources.
QAPP Information: | Data meet the quality assurance requirements of the SWAMP QAPP.
QAPP Information Reference(s):

DECISION ID | 20821 | Region 6
Mesquite Springs (Inyo County)

Pollutant: | Lithium
Final Listing Decision: | Do Not List on 303(d) list (TMDL required list)
Last Listing Cycle's Final Listing Decision: | Do Not List on 303(d) list (TMDL required list)(2010)
Revision Status | Original
Impairment from Pollutant or Pollution: | Pollutant
Regional Board Staff Conclusion: | This pollutant was considered for placement on the section 303(d) list in a previous assessment cycle. No new information was reviewed for this current assessment cycle. Therefore, the previous conclusion remains unchanged, and is as follows: This pollutant is being considered for placement on the section 303(d) list under section 3.1 of the Listing Policy. Under section 3.1 a single line of evidence is necessary to assess listing status. Two lines of evidence are available in the administrative record to assess this pollutant. There are no California or federal criteria, standards, or water quality objectives applicable to lithium. Based on the readily available data and information, the weight of evidence indicates that there is sufficient justification against placing this water segment-pollutant combination on the section 303(d) list in the Water Quality Limited Segments category.
Regional Board Staff Decision Recommendation: | No new data were assessed for this assessment cycle. The conclusion reached in the previous cycle remains in same. The Regional Board will update this decision when new data and information become available in a future assessment cycle.

Line of Evidence (LOE) for Decision ID 20821, Lithium | Region 6
Mesquite Springs (Inyo County)
LOE ID: | 6226
Pollutant: | Lithium
LOE Subgroup: | Pollutant-Water
Matrix: | Water
Fraction: | Dissolved
Beneficial Use: | Municipal & Domestic Supply
Number of Samples: | 2
Number of Exceedances: | 0
Data and Information Type: | Fixed station physical/chemical (conventional plus toxic pollutants)
Data Used to Assess Water Quality: | The U.S. Geological Survey sampled Mesquite Springs under the Region 6 SWAMP program in 2002 and 2003. Dissolved lithium concentrations in two samples were 219 and 186 ug/L.
Data Reference: | 2007. SWAMP Data for the Amargosa Hydrologic Unit
SWAMP Data: | SWAMP
Water Quality Objective/Criterion: | There are no state or federal water quality standards or criteria for lithium.
Objective/Criterion Reference: | Water Quality Control Plan for the Lahontan Region (as amended)
Evaluation Guideline: |
Guideline Reference:
Spatial Representation: | One station, Mesquite Spring (in Death Valley National Park, near Scottys Castle), was sampled.
Temporal Representation: | Two samples were collected in 2002 and 2003.
Environmental Conditions: | The Mesquite Springs are within the Stovepipe Wells Hydrologic Subarea of the Amargosa Hydrologic Unit (HU No. 609.11). They supply drinking water to a campground. No site-specific water quality objectives apply to the springs. Chemical and radioactive constituents come from natural sources.
QAPP Information: | Data meet the quality assurance requirements of the SWAMP QAPP.
QAPP Information Reference(s):
Line of Evidence (LOE) for Decision ID 20821, Lithium | Region 6
Mesquite Springs (Inyo County)
LOE ID: | 6225
Pollutant: | Lithium
LOE Subgroup: | Pollutant-Water
Matrix: | Water
Fraction: | Dissolved
Beneficial Use: | Cold Freshwater Habitat
Number of Samples: | 2
Number of Exceedances: | 0
Data and Information Type: | Fixed station physical/chemical (conventional plus toxic pollutants)
Data Used to Assess Water Quality: | The U.S. Geological Survey sampled Mesquite Springs under the Region 6 SWAMP program in 2002 and 2003. Dissolved lithium concentrations in two samples were 219 and 186 ug/L.
Data Reference: | 2007. SWAMP Data for the Amargosa Hydrologic Unit
SWAMP Data: | SWAMP
Water Quality Objective/Criterion: | There are no state or federal water quality standards or criteria for lithium.
Objective/Criterion Reference: | Water Quality Control Plan for the Lahontan Region (as amended)
Evaluation Guideline: |
Guideline Reference:
Spatial Representation: | One station, Mesquite Spring (in Death Valley National Park, near Scottys Castle), was sampled.
Temporal Representation: | Two samples were collected in 2002 and 2003.
Environmental Conditions: | The Mesquite Springs are within the Stovepipe Wells Hydrologic Subarea of the Amargosa Hydrologic Unit (HU No. 609.11). They supply drinking water to a campground. No site-specific water quality objectives apply to the springs. Chemical and radioactive constituents come from natural sources.
QAPP Information: | Data meet the quality assurance requirements of the SWAMP QAPP.
QAPP Information Reference(s):

DECISION ID | 23391 | Region 6
Mesquite Springs (Inyo County)

Pollutant: | Magnesium
Final Listing Decision: | Do Not List on 303(d) list (TMDL required list)
Last Listing Cycle's Final Listing Decision: | Do Not List on 303(d) list (TMDL required list)(2010)
Revision Status | Original
Impairment from Pollutant or Pollution: | Pollutant
Regional Board Staff Conclusion: | This pollutant was considered for placement on the section 303(d) list in a previous assessment cycle. No new information was reviewed for this current assessment cycle. Therefore, the previous conclusion remains unchanged, and is as follows: This pollutant is being considered for placement on the section 303(d) list under section 3.2 of the Listing Policy. Under section 3.2 a single line of evidence is necessary to assess listing status. Two lines of evidence are available in the administrative record to assess this pollutant. There are no applicable California of federal water quality standards or criteria for magnesium. Based on the readily available data and information, the weight of evidence indicates that there is sufficient justification against placing this water segment-pollutant combination on the section 303(d) list in the Water Quality Limited Segments category. This conclusion is based on the staff findings that: 1. The data used satisfy the data quality requirements of section 6.1.4 of the Policy. 2. The data used do not satisfy the data quantity requirements of section 6.1.5 of the Policy. 3. There are no applicable standards or criteria and the data cannot be assessed using Table 3.2 of the Listing Policy. 4. Pursuant to section 3.11 of the Listing Policy, no additional data and information are available indicating that standards are not met.
Regional Board Staff Decision Recommendation: | No new data were assessed for this assessment cycle. The conclusion reached in the previous cycle remains in same. The Regional Board will update this decision when new data and information become available in a future assessment cycle.

Line of Evidence (LOE) for Decision ID 23391, Magnesium | Region 6
Mesquite Springs (Inyo County)
LOE ID: | 21251
Pollutant: | Magnesium
LOE Subgroup: | Pollutant-Water
Matrix: | Water
Fraction: | Dissolved
Beneficial Use: | Cold Freshwater Habitat
Number of Samples: | 2
Number of Exceedances: | 0
Data and Information Type: | Fixed station physical/chemical (conventional plus toxic pollutants)
Data Used to Assess Water Quality: | The U.S. Geological Survey sampled Mesquite Springs under the Region 6 SWAMP program in 2002 and 2003. The concentrations of dissolved magnesium in two samples were 14.1 and 14.2 mg/L.
Data Reference: | 2007. SWAMP Data for the Amargosa Hydrologic Unit
SWAMP Data: | SWAMP
Water Quality Objective/Criterion: | There are no state or federal standards, water quality objectives or criteria for magnesium.
Objective/Criterion Reference: | Water Quality Control Plan for the Lahontan Region (as amended)
Evaluation Guideline: |
Guideline Reference:
Spatial Representation: | One station, Mesquite Spring (in Death Valley National Park, near Scottys Castle), was sampled.
Temporal Representation: | Two samples were collected in 2002 and 2003.
Environmental Conditions: | The Mesquite Springs are within the Stovepipe Wells Hydrologic Subarea of the Amargosa Hydrologic Unit (HU No. 609.11). They supply drinking water to a campground. No site-specific water quality objectives apply to the springs. Chemical and radioactive constituents come from natural sources.
QAPP Information: | Data meet the quality assurance requirements of the SWAMP QAPP.
QAPP Information Reference(s):

DECISION ID | 20905 | Region 6
Mesquite Springs (Inyo County)

Pollutant: | Manganese
Final Listing Decision: | Do Not List on 303(d) list (TMDL required list)
Last Listing Cycle's Final Listing Decision: | Do Not List on 303(d) list (TMDL required list)(2010)
Revision Status | Original
Impairment from Pollutant or Pollution: | Pollutant
Regional Board Staff Conclusion: | This pollutant was considered for placement on the section 303(d) list in a previous assessment cycle. No new information was reviewed for this current assessment cycle. Therefore, the previous conclusion remains unchanged, and is as follows: This pollutant is being considered for placement on the section 303(d) list under section 3.1 of the Listing Policy. Under section 3.1 a single line of evidence is necessary to assess listing status. One line of evidence is available in the administrative record to assess this pollutant. None of the samples exceed the water quality objective. Based on the readily available data and information, the weight of evidence indicates that there is sufficient justification against placing this water segment-pollutant combination on the section 303(d) list in the Water Quality Limited Segments category. This conclusion is based on the staff findings that: 1. The data used satisfy the data quality requirements of section 6.1.4 of the Policy. 2. The data used do not satisfy the data quantity requirements of section 6.1.5 of the Policy. Only one sample per year was taken. 3. Neither of two samples exceeded the water quality objective and this does not exceed the allowable frequency listed in Table 3.1 of the Listing Policy. 4. Pursuant to section 3.11 of the Listing Policy, no additional data and information are available indicating that standards are not met.
Regional Board Staff Decision Recommendation: | No new data were assessed for this assessment cycle. The conclusion reached in the previous cycle remains in same. The Regional Board will update this decision when new data and information become available in a future assessment cycle.

Line of Evidence (LOE) for Decision ID 20905, Manganese | Region 6
Mesquite Springs (Inyo County)
LOE ID: | 5312
Pollutant: | Manganese
LOE Subgroup: | Pollutant-Water
Matrix: | Water
Fraction: | Dissolved
Beneficial Use: | Municipal & Domestic Supply
Number of Samples: | 2
Number of Exceedances: | 0
Data and Information Type: | Fixed station physical/chemical (conventional plus toxic pollutants)
Data Used to Assess Water Quality: | The U.S. Geological Survey sampled Mesquite Springs under the Region 6 SWAMP program in 2002 and 2003. The manganese concentration in one of two samples was below detection level and the other was 0.3 ug/L. The MCL was not exceeded. (Note: MCLs for metals are expressed as total rather than dissolved.)
Data Reference: | 2007. SWAMP Data for the Amargosa Hydrologic Unit
SWAMP Data: | SWAMP
Water Quality Objective/Criterion: | California Maximum Contaminant Levels (MCLs) apply to ambient waters under the Lahontan Basin Plan's "Chemical Constituents" objective. The MCL for manganese is 50 ug/L.
Objective/Criterion Reference: | Water Quality Standards 2000. Establishment of numeric criteria for priority toxic pollutants for the State of California: Rules and regulations. Federal Register Vol. 65, No. 97. Washington, D.C.: Environmental Protection Agency
Evaluation Guideline: |
Guideline Reference:
Spatial Representation: | One station, Mesquite Spring (in Death Valley National Park, near Scottys Castle), was sampled.
Temporal Representation: | Two samples were collected in 2002 and 2003.
Environmental Conditions: | The Mesquite Springs are within the Stovepipe Wells Hydrologic Subarea of the Amargosa Hydrologic Unit (HU No. 609.11). They supply drinking water to a campground. No site-specific water quality objectives apply to the springs. Chemical and radioactive constituents come from natural sources.
QAPP Information: | Data meet the quality assurance requirements of the SWAMP QAPP.
QAPP Information Reference(s):

DECISION ID | 20765 | Region 6
Mesquite Springs (Inyo County)

Pollutant: | Molybdenum
Final Listing Decision: | Do Not List on 303(d) list (TMDL required list)
Last Listing Cycle's Final Listing Decision: | Do Not List on 303(d) list (TMDL required list)(2010)
Revision Status | Original
Impairment from Pollutant or Pollution: | Pollutant
Regional Board Staff Conclusion: | This pollutant was considered for placement on the section 303(d) list in a previous assessment cycle. No new information was reviewed for this current assessment cycle. Therefore, the previous conclusion remains unchanged, and is as follows: This pollutant is being considered for placement on the section 303(d) list under section 3.1 of the Listing Policy. Under section 3.1 a single line of evidence is necessary to assess listing status. One line of evidence is available in the administrative record to assess this pollutant. There are no applicable water quality standards or criteria. Based on the readily available data and information, the weight of evidence indicates that there is sufficient justification against placing this water segment-pollutant combination on the section 303(d) list in the Water Quality Limited Segments category. This conclusion is based on the staff findings that: 1. The data used satisfy the data quality requirements of section 6.1.4 of the Policy. 2. The data used do not satisfy the data quantity requirements of section 6.1.5 of the Policy in that only one sample per year is available. 3. There are no applicable water quality standards or criteria and the data cannot be assessed using Table 3.1 of the Listing Policy. 4. Pursuant to section 3.11 of the Listing Policy, no additional data and information are available indicating that standards are not met.
Regional Board Staff Decision Recommendation: | No new data were assessed for this assessment cycle. The conclusion reached in the previous cycle remains in same. The Regional Board will update this decision when new data and information become available in a future assessment cycle.

Line of Evidence (LOE) for Decision ID 20765, Molybdenum | Region 6
Mesquite Springs (Inyo County)
LOE ID: | 5799
Pollutant: | Molybdenum
LOE Subgroup: | Pollutant-Water
Matrix: | Water
Fraction: | Dissolved
Beneficial Use: | Municipal & Domestic Supply
Number of Samples: | 2
Number of Exceedances: | 0
Data and Information Type: | Fixed station physical/chemical (conventional plus toxic pollutants)
Data Used to Assess Water Quality: | The U.S. Geological Survey sampled Mesquite Springs under the Region 6 SWAMP program in 2002 and 2003. Dissolved molybdenum concentrations in two samples were 15.5 and 16.6 ug/L.
Data Reference: | 2007. SWAMP Data for the Amargosa Hydrologic Unit
SWAMP Data: | SWAMP
Water Quality Objective/Criterion: | There are no applicable water quality standards or criteria for molybdenum for protection of the Municipal and Domestic Supply beneficial use.
Objective/Criterion Reference: | Water Quality Control Plan for the Lahontan Region (as amended)
Evaluation Guideline: |
Guideline Reference:
Spatial Representation: | One station, Mesquite Spring (in Death Valley National Park, near Scottys Castle), was sampled.
Temporal Representation: | Two samples were collected in 2002 and 2003.
Environmental Conditions: | The Mesquite Springs are within the Stovepipe Wells Hydrologic Subarea of the Amargosa Hydrologic Unit (HU No. 609.11). They supply drinking water to a campground. No site-specific water quality objectives apply to the springs. Chemical and radioactive constituents come from natural sources.
QAPP Information: | Data meet the quality assurance requirements of the SWAMP QAPP.
QAPP Information Reference(s):

DECISION ID | 21280 | Region 6
Mesquite Springs (Inyo County)

Pollutant: | Nickel
Final Listing Decision: | Do Not List on 303(d) list (TMDL required list)
Last Listing Cycle's Final Listing Decision: | Do Not List on 303(d) list (TMDL required list)(2010)
Revision Status | Original
Impairment from Pollutant or Pollution: | Pollutant
Regional Board Staff Conclusion: | This pollutant was considered for placement on the section 303(d) list in a previous assessment cycle. No new information was reviewed for this current assessment cycle. Therefore, the previous conclusion remains unchanged, and is as follows: This pollutant is being considered for placement on the section 303(d) list under section 3.1 of the Listing Policy. Under section 3.1 a single line of evidence is necessary to assess listing status. Two lines of evidence are available in the administrative record to assess this pollutant. None of the samples exceeds the California Maximum Contaminant Level or Toxics Rule standards. Based on the readily available data and information, the weight of evidence indicates that there is sufficient justification against placing this water segment-pollutant combination on the section 303(d) list in the Water Quality Limited Segments category. This conclusion is based on the staff findings that: 1. The data used satisfy the data quality requirements of section 6.1.4 of the Policy. 2. The data used do not satisfy the data quantity requirements of section 6.1.5 of the Policy in that only one sample per year is available. 3. Neither of two samples exceeded the applicable California Maximum Contaminant Level or California Toxics Rule standard, and this does not exceed the allowable frequency listed in Table 3.1 of the Listing Policy. 4. Pursuant to section 3.11 of the Listing Policy, no additional data and information are available indicating that standards are not met.
Regional Board Staff Decision Recommendation: | No new data were assessed for this assessment cycle. The conclusion reached in the previous cycle remains in same. The Regional Board will update this decision when new data and information become available in a future assessment cycle.

Line of Evidence (LOE) for Decision ID 21280, Nickel | Region 6
Mesquite Springs (Inyo County)
LOE ID: | 5314
Pollutant: | Nickel
LOE Subgroup: | Pollutant-Water
Matrix: | Water
Fraction: | Dissolved
Beneficial Use: | Municipal & Domestic Supply
Number of Samples: | 2
Number of Exceedances: | 0
Data and Information Type: | Fixed station physical/chemical (conventional plus toxic pollutants)
Data Used to Assess Water Quality: | The U.S. Geological Survey sampled Mesquite Springs under the Region 6 SWAMP program in 2002 and 2003. The nickel concentrations in two samples were 1.34 and 0.6 ug/L. The MCL was not exceeded. (Note: MCLs for metals are expressed as total rather than dissolved.)
Data Reference: | 2007. SWAMP Data for the Amargosa Hydrologic Unit
SWAMP Data: | SWAMP
Water Quality Objective/Criterion: | California Maximum Contaminant Levels (MCLs) apply to ambient waters under the Lahontan Basin Plan's "Chemical Constituents" objective. The MCL for nickel is 100 ug/L.
Objective/Criterion Reference: | Water Quality Control Plan for the Lahontan Region (as amended)
Evaluation Guideline: |
Guideline Reference:
Spatial Representation: | One station, Mesquite Spring (in Death Valley National Park, near Scottys Castle), was sampled.
Temporal Representation: | Two samples were collected in 2002 and 2003.
Environmental Conditions: | The Mesquite Springs are within the Stovepipe Wells Hydrologic Subarea of the Amargosa Hydrologic Unit (HU No. 609.11). They supply drinking water to a campground. No site-specific water quality objectives apply to the springs. Chemical and radioactive constituents come from natural sources.
QAPP Information: | Data meet the quality assurance requirements of the SWAMP QAPP.
QAPP Information Reference(s):
Line of Evidence (LOE) for Decision ID 21280, Nickel | Region 6
Mesquite Springs (Inyo County)
LOE ID: | 5802
Pollutant: | Nickel
LOE Subgroup: | Pollutant-Water
Matrix: | Water
Fraction: | Dissolved
Beneficial Use: | Cold Freshwater Habitat
Number of Samples: | 2
Number of Exceedances: | 0
Data and Information Type: | Fixed station physical/chemical (conventional plus toxic pollutants)
Data Used to Assess Water Quality: | The U.S. Geological Survey sampled Mesquite Springs under the Region 6 SWAMP program in 2002 and 2003. The nickel concentrations in two samples were 1.34 and 0.6 ug/L. The CTR standards for acute and chronic toxicity were not exceeded.
Data Reference: | 2007. SWAMP Data for the Amargosa Hydrologic Unit
SWAMP Data: | SWAMP
Water Quality Objective/Criterion: | The California Toxics Rule's (CTR's) freshwater aquatic life standards for nickel are dependent on hardness. At the observed hardness values for the Mesquite Springs samples (123 and 125 mg/L CaCO3) the applicable acute toxicity standards are 557.82 and 565.52 ug/L. The applicable chronic toxicity standards are 62.022 and 62.88 ug/L.
Objective/Criterion Reference: | Water Quality Standards 2000. Establishment of numeric criteria for priority toxic pollutants for the State of California: Rules and regulations. Federal Register Vol. 65, No. 97. Washington, D.C.: Environmental Protection Agency
Evaluation Guideline: |
Guideline Reference:
Spatial Representation: | One station, Mesquite Spring (in Death Valley National Park, near Scottys Castle), was sampled.
Temporal Representation: | Two samples were collected in 2002 and 2003.
Environmental Conditions: | The Mesquite Springs are within the Stovepipe Wells Hydrologic Subarea of the Amargosa Hydrologic Unit (HU No. 609.11). They supply drinking water to a campground. No site-specific water quality objectives apply to the springs. Chemical and radioactive constituents come from natural sources.
QAPP Information: | Data meet the quality assurance requirements of the SWAMP QAPP.
QAPP Information Reference(s):

DECISION ID | 22630 | Region 6
Mesquite Springs (Inyo County)

Pollutant: | Nitrate
Final Listing Decision: | Do Not List on 303(d) list (TMDL required list)
Last Listing Cycle's Final Listing Decision: | Do Not List on 303(d) list (TMDL required list)(2010)
Revision Status | Original
Impairment from Pollutant or Pollution: | Pollutant
Regional Board Staff Conclusion: | This pollutant was considered for placement on the section 303(d) list in a previous assessment cycle. No new information was reviewed for this current assessment cycle. Therefore, the previous conclusion remains unchanged, and is as follows: This pollutant is being considered for placement on the section 303(d) list under section 3.1 of the Listing Policy. Under section 3.1 a single line of evidence is necessary to assess listing status. One of evidence is available in the administrative record to assess this pollutant. None of the samples exceeds the California Maximum Contaminant Level (MCL). Based on the readily available data and information, the weight of evidence indicates that there is sufficient justification against placing this water segment-pollutant combination on the section 303(d) list in the Water Quality Limited Segments category. This conclusion is based on the staff findings that: 1. The data used satisfy the data quality requirements of section 6.1.4 of the Policy. 2. The data used do not satisfy the data quantity requirements of section 6.1.5 of the Policy because only one sample per year is available. 3. Neither of two annual samples exceeded the MCL and this does not exceed the allowable frequency listed in Table 3.1 of the Listing Policy. 4. Pursuant to section 3.11 of the Listing Policy, no additional data and information are available indicating that standards are not met.
Regional Board Staff Decision Recommendation: | No new data were assessed for this assessment cycle. The conclusion reached in the previous cycle remains in same. The Regional Board will update this decision when new data and information become available in a future assessment cycle.

Line of Evidence (LOE) for Decision ID 22630, Nitrate | Region 6
Mesquite Springs (Inyo County)
LOE ID: | 5617
Pollutant: | Nitrate
LOE Subgroup: | Pollutant-Water
Matrix: | Water
Fraction: | Dissolved
Beneficial Use: | Municipal & Domestic Supply
Number of Samples: | 2
Number of Exceedances: | 0
Data and Information Type: | Not Specified
Data Used to Assess Water Quality: | The U.S. Geological Survey sampled Mesquite Springs under the Region 6 SWAMP program. The reported concentrations of nitrite in two samples were below the detection level. The reported nitrate plus nitrite concentrations in two samples were 0.205 and 0.272 mg/L. Since these are equivalent to the nitrate concentrations in the two samples, the MCL for nitrate was not violated.
Data Reference: | 2007. SWAMP Data for the Amargosa Hydrologic Unit
SWAMP Data: | SWAMP
Water Quality Objective/Criterion: | California Maximum Contaminant Levels (MCLs) apply to ambient waters under the Lahontan Basin Plan's "Chemical Constituents" objective. The MCL for nitrate is 45 mg/L as nitrate, equivalent to 10 mg/L nitrate as N.
Objective/Criterion Reference: | Water Quality Control Plan for the Lahontan Region (as amended)
Evaluation Guideline: |
Guideline Reference:
Spatial Representation: | One station, Mesquite Spring (in Death Valley National Park, near Scottys Castle), was sampled.
Temporal Representation: | Two samples each for nitrate plus nitrite and nitrite were collected in 2002 and 2003.
Environmental Conditions: | The Mesquite Springs are within the Stovepipe Wells Hydrologic Subarea of the Amargosa Hydrologic Unit (HU No. 609.11). They supply drinking water to a campground. No site-specific water quality objectives apply to the springs. Chemical and radioactive constituents come from natural sources.
QAPP Information: | Data meet the quality assurance requirements of the SWAMP QAPP.
QAPP Information Reference(s):

DECISION ID | 25293 | Region 6
Mesquite Springs (Inyo County)

Pollutant: | Nitrate/Nitrite (Nitrite + Nitrate as N)
Final Listing Decision: | Do Not List on 303(d) list (TMDL required list)
Last Listing Cycle's Final Listing Decision: | Do Not List on 303(d) list (TMDL required list)(2010)
Revision Status | Original
Impairment from Pollutant or Pollution: | Pollutant
Regional Board Staff Conclusion: | This pollutant was considered for placement on the section 303(d) list in a previous assessment cycle. No new information was reviewed for this current assessment cycle. Therefore, the previous conclusion remains unchanged, and is as follows: This pollutant is being considered for placement on the section 303(d) list under section 3.1 of the Listing Policy. Under section 3.1 a single line of evidence is necessary to assess listing status. One of evidence is available in the administrative record to assess this pollutant. Neither of the samples exceeds the California Maximum Contaminant Level (MCL). Based on the readily available data and information, the weight of evidence indicates that there is sufficient justification against placing this water segment-pollutant combination on the section 303(d) list in the Water Quality Limited Segments category. This conclusion is based on the staff findings that: 1. The data used satisfy the data quality requirements of section 6.1.4 of the Policy. 2. The data used do not satisfy the data quantity requirements of section 6.1.5 of the Policy in that only one sample per year is available. 3. Neither of two samples exceeded the MCL and this does not exceed the allowable frequency listed in Table 3.1 of the Listing Policy. 4. Pursuant to section 3.11 of the Listing Policy, no additional data and information are available indicating that standards are not met.
Regional Board Staff Decision Recommendation: | No new data were assessed for this assessment cycle. The conclusion reached in the previous cycle remains in same. The Regional Board will update this decision when new data and information become available in a future assessment cycle.

Line of Evidence (LOE) for Decision ID 25293, Nitrate/Nitrite (Nitrite + Nitrate as N) | Region 6
Mesquite Springs (Inyo County)
LOE ID: | 21248
Pollutant: | Nitrate/Nitrite (Nitrite + Nitrate as N)
LOE Subgroup: | Pollutant-Water
Matrix: | Water
Fraction: | Dissolved
Beneficial Use: | Municipal & Domestic Supply
Number of Samples: | 2
Number of Exceedances: | 0
Data and Information Type: | Not Specified
Data Used to Assess Water Quality: | The U.S. Geological Survey sampled Mesquite Springs under the Region 6 SWAMP program. The concentrations of nitrite plus nitrate in two samples were 0.205 and 0.272 mg/L. The MCL was not exceeded.
Data Reference: | 2007. SWAMP Data for the Amargosa Hydrologic Unit
SWAMP Data: | SWAMP
Water Quality Objective/Criterion: | California Maximum Contaminant Levels (MCLs) apply to ambient waters under the Lahontan Basin Plan's "Chemical Constituents" objective. The MCL for nitrite plus nitrate is 10 mg/L.
Objective/Criterion Reference: | Water Quality Control Plan for the Lahontan Region (as amended)
Evaluation Guideline: |
Guideline Reference:
Spatial Representation: | One station, Mesquite Spring (in Death Valley National Park, near Scottys Castle), was sampled.
Temporal Representation: | Two samples were collected in 2002 and 2003.
Environmental Conditions: | The Mesquite Springs are within the Stovepipe Wells Hydrologic Subarea of the Amargosa Hydrologic Unit (HU No. 609.11). They supply drinking water to a campground. No site-specific water quality objectives apply to the springs. Chemical and radioactive constituents come from natural sources.
QAPP Information: | Data meet the quality assurance requirements of the SWAMP QAPP.
QAPP Information Reference(s):

DECISION ID | 23035 | Region 6
Mesquite Springs (Inyo County)

Pollutant: | Nitrite
Final Listing Decision: | Do Not List on 303(d) list (TMDL required list)
Last Listing Cycle's Final Listing Decision: | Do Not List on 303(d) list (TMDL required list)(2010)
Revision Status | Original
Impairment from Pollutant or Pollution: | Pollutant
Regional Board Staff Conclusion: | This pollutant was considered for placement on the section 303(d) list in a previous assessment cycle. No new information was reviewed for this current assessment cycle. Therefore, the previous conclusion remains unchanged, and is as follows: This pollutant is being considered for placement on the section 303(d) list under section 3.1 of the Listing Policy. Under section 3.1 a single line of evidence is necessary to assess listing status. One line of evidence is available in the administrative record to assess this pollutant. Neither of the samples exceeds the California Maximum Contaminant Level (MCL). Based on the readily available data and information, the weight of evidence indicates that there is sufficient justification against placing this water segment-pollutant combination on the section 303(d) list in the Water Quality Limited Segments category. This conclusion is based on the staff findings that: 1. The data used satisfy the data quality requirements of section 6.1.4 of the Policy. 2. The data used satisfy the data quantity requirements of section 6.1.5 of the Policy. 3. Neither of two samples exceeded the MCL and this does not exceed the allowable frequency listed in Table 3.1 of the Listing Policy. 4. Pursuant to section 3.11 of the Listing Policy, no additional data and information are available indicating that standards are not met.
Regional Board Staff Decision Recommendation: | No new data were assessed for this assessment cycle. The conclusion reached in the previous cycle remains in same. The Regional Board will update this decision when new data and information become available in a future assessment cycle.

Line of Evidence (LOE) for Decision ID 23035, Nitrite | Region 6
Mesquite Springs (Inyo County)
LOE ID: | 5616
Pollutant: | Nitrite
LOE Subgroup: | Pollutant-Water
Matrix: | Water
Fraction: | Dissolved
Beneficial Use: | Municipal & Domestic Supply
Number of Samples: | 2
Number of Exceedances: | 0
Data and Information Type: | Not Specified
Data Used to Assess Water Quality: | The U.S. Geological Survey sampled Mesquite Springs under the Region 6 SWAMP program. Nitrite concentrations in two samples were below the detection level. Per Listing Policy Section 6.1.5.5, the MCL is presumed to be attained.
Data Reference: | 2007. SWAMP Data for the Amargosa Hydrologic Unit
SWAMP Data: | SWAMP
Water Quality Objective/Criterion: | California Maximum Contaminant Levels (MCLs) apply to ambient waters under the Lahontan Basin Plan's "Chemical Constituents" objective. The MCL for nitrite is 1 mg/L.
Objective/Criterion Reference: | Water Quality Control Plan for the Lahontan Region (as amended)
Evaluation Guideline: |
Guideline Reference:
Spatial Representation: | One station, Mesquite Spring (in Death Valley National Park, near Scottys Castle), was sampled.
Temporal Representation: | Two samples were collected in 2002 and 2003.
Environmental Conditions: | The Mesquite Springs are within the Stovepipe Wells Hydrologic Subarea of the Amargosa Hydrologic Unit (HU No. 609.11). They supply drinking water to a campground. No site-specific water quality objectives apply to the springs. Chemical and radioactive constituents come from natural sources.
QAPP Information: | Data meet the quality assurance requirements of the SWAMP QAPP.
QAPP Information Reference(s):

DECISION ID | 23333 | Region 6
Mesquite Springs (Inyo County)

Pollutant: | Oxygen 18/Oxygen 16 ratio
Final Listing Decision: | Do Not List on 303(d) list (TMDL required list)
Last Listing Cycle's Final Listing Decision: | Do Not List on 303(d) list (TMDL required list)(2010)
Revision Status | Original
Impairment from Pollutant or Pollution: | Pollutant
Regional Board Staff Conclusion: | This pollutant was considered for placement on the section 303(d) list in a previous assessment cycle. No new information was reviewed for this current assessment cycle. Therefore, the previous conclusion remains unchanged, and is as follows: This pollutant is being considered for placement on the section 303(d) list under section 3.2 of the Listing Policy. Under section 3.2 a single line of evidence is necessary to assess listing status. Two lines of evidence are available in the administrative record to assess this pollutant. There are no California or federal criteria, standards, or water quality objectives applicable to oxygen 18/oxygen 16 ratio. Based on the readily available data and information, the weight of evidence indicates that there is sufficient justification against placing this water segment-pollutant combination on the section 303(d) list in the Water Quality Limited Segments category.
Regional Board Staff Decision Recommendation: | No new data were assessed for this assessment cycle. The conclusion reached in the previous cycle remains in same. The Regional Board will update this decision when new data and information become available in a future assessment cycle.

Line of Evidence (LOE) for Decision ID 23333, Oxygen 18/Oxygen 16 ratio | Region 6
Mesquite Springs (Inyo County)
LOE ID: | 21285
Pollutant: | Oxygen 18/Oxygen 16 ratio
LOE Subgroup: | Pollutant-Water
Matrix: | Water
Fraction: | Dissolved
Beneficial Use: | Cold Freshwater Habitat
Number of Samples: | 2
Number of Exceedances: | 0
Data and Information Type: | Fixed station physical/chemical (conventional plus toxic pollutants)
Data Used to Assess Water Quality: | The U.S. Geological Survey sampled Mesquite Springs under the Region 6 SWAMP program in 2002 and 2003. The reported oxygen 18/oxygen 16 ratios (as ml) in two samples were -13.84 and -13.86.
Data Reference: | 2007. SWAMP Data for the Amargosa Hydrologic Unit
SWAMP Data: | SWAMP
Water Quality Objective/Criterion: | There are no state or federal standards, water quality objectives or criteria for oxygen 18/oxygen 16 ratio.
Objective/Criterion Reference: | Water Quality Control Plan for the Lahontan Region (as amended)
Evaluation Guideline: |
Guideline Reference:
Spatial Representation: | One station, Mesquite Spring (in Death Valley National Park, near Scottys Castle), was sampled.
Temporal Representation: | Two samples were collected in 2002 and 2003.
Environmental Conditions: | The Mesquite Springs are within the Stovepipe Wells Hydrologic Subarea of the Amargosa Hydrologic Unit (HU No. 609.11). They supply drinking water to a campground. No site-specific water quality objectives apply to the springs. Chemical and radioactive constituents come from natural sources.
QAPP Information: | Data meet the quality assurance requirements of the SWAMP QAPP.
QAPP Information Reference(s):

DECISION ID | 20836 | Region 6
Mesquite Springs (Inyo County)

Pollutant: | Oxygen, Dissolved
Final Listing Decision: | Do Not List on 303(d) list (TMDL required list)
Last Listing Cycle's Final Listing Decision: | Do Not List on 303(d) list (TMDL required list)(2010)
Revision Status | Original
Impairment from Pollutant or Pollution: | Pollutant
Regional Board Staff Conclusion: | This pollutant was considered for placement on the section 303(d) list in a previous assessment cycle. No new information was reviewed for this current assessment cycle. Therefore, the previous conclusion remains unchanged, and is as follows: This pollutant is being considered for placement on the section 303(d) list under section 3.2 of the Listing Policy. Under section 3.2 a single line of evidence is necessary to assess listing status. One line of evidence is available in the administrative record to assess this pollutant. None of the samples exceeds the water quality objective. Based on the readily available data and information, the weight of evidence indicates that there is sufficient justification against placing this water segment-pollutant combination on the section 303(d) list in the Water Quality Limited Segments category. This conclusion is based on the staff findings that: 1. The data used satisfy the data quality requirements of section 6.1.4 of the Policy. 2. The data used do not satisfy the data quantity requirements of section 6.1.5 of the Policy in that only one sample per year is available. 3. Neither of two samples exceeded the water quality objective and this does not exceed the allowable frequency listed in Table 3.2 of the Listing Policy. 4. Pursuant to section 3.11 of the Listing Policy, no additional data and information are available indicating that standards are not met.
Regional Board Staff Decision Recommendation: | No new data were assessed for this assessment cycle. The conclusion reached in the previous cycle remains in same. The Regional Board will update this decision when new data and information become available in a future assessment cycle.

Line of Evidence (LOE) for Decision ID 20836, Oxygen, Dissolved | Region 6
Mesquite Springs (Inyo County)
LOE ID: | 5246
Pollutant: | Oxygen, Dissolved
LOE Subgroup: | Pollutant-Water
Matrix: | Water
Fraction: | Dissolved
Beneficial Use: | Cold Freshwater Habitat
Number of Samples: | 2
Number of Exceedances: | 0
Data and Information Type: | Fixed station physical/chemical (conventional plus toxic pollutants)
Data Used to Assess Water Quality: | The U.S. Geological Survey sampled Mesquite Springs under the Region 6 SWAMP program. Dissolved oxygen concentrations in two samples were 7.5 and 8.3 mg/L.The objective was not exceeded, but sample numbers were too small for use with the Listing Policy's binomial model.
Data Reference: | 2007. SWAMP Data for the Amargosa Hydrologic Unit
SWAMP Data: | SWAMP
Water Quality Objective/Criterion: | The applicable objective from Lahontan Basin Plan Table 3-6 is a 1- day minimum dissolved oxygen concentration of 4.0 mg/L for waters designated for the Cold Freshwater Habitat Use.
Objective/Criterion Reference: | Water Quality Control Plan for the Lahontan Region (as amended)
Evaluation Guideline: |
Guideline Reference:
Spatial Representation: | One station, Mesquite Spring (in Death Valley National Park, near Scottys Castle), was sampled.
Temporal Representation: | Two dissolved oxygen samples were taken in 2002 and 2003.
Environmental Conditions: | The Mesquite Springs are within the Stovepipe Wells Hydrologic Subarea of the Amargosa Hydrologic Unit (HU No. 609.11). They supply drinking water to a campground. No site-specific water quality objectives apply to the springs. Chemical and radioactive constituents, including the salts that contribute to high specific conductance levels, come from natural sources. The Mesquite Springs are designated for both the Warm Freshwater Habitat and Cold Freshwater Habitat beneficial uses, and for the Rare, Threatened or Endangered Species Use.
QAPP Information: | Data meet the quality assurance requirements of the SWAMP QAPP.
QAPP Information Reference(s):

DECISION ID | 23482 | Region 6
Mesquite Springs (Inyo County)

Pollutant: | Phosphate
Final Listing Decision: | Do Not List on 303(d) list (TMDL required list)
Last Listing Cycle's Final Listing Decision: | Do Not List on 303(d) list (TMDL required list)(2010)
Revision Status | Original
Impairment from Pollutant or Pollution: | Pollutant
Regional Board Staff Conclusion: | This pollutant was considered for placement on the section 303(d) list in a previous assessment cycle. No new information was reviewed for this current assessment cycle. Therefore, the previous conclusion remains unchanged, and is as follows: This pollutant is being considered for placement on the section 303(d) list under section 3.1 of the Listing Policy. Under section 3.1 a single line of evidence is necessary to assess listing status. One line line(s) of evidence is available in the administrative record to assess this pollutant. There are no biological data available to assess whether any of the of the chemical samples exceeds the water quality objective. Based on the readily available data and information, the weight of evidence indicates that there is sufficient justification against placing this water segment-pollutant combination on the section 303(d) list in the Water Quality Limited Segments category. This conclusion is based on the staff findings that: 1. The data used satisfy the data quality requirements of section 6.1.4 of the Policy. 2. The data used do not satisfy the data quantity requirements of section 6.1.5 of the Policy in that only one sample per year is available. 3. There are no biological data available to evaluate compliance with the objective and the data cannot be assessed using Table 3.1 of the Listing Policy. 4. Pursuant to section 3.11 of the Listing Policy, no additional data and information are available indicating that standards are not met.
Regional Board Staff Decision Recommendation: | No new data were assessed for this assessment cycle. The conclusion reached in the previous cycle remains in same. The Regional Board will update this decision when new data and information become available in a future assessment cycle.

Line of Evidence (LOE) for Decision ID 23482, Phosphate | Region 6
Mesquite Springs (Inyo County)
LOE ID: | 6035
Pollutant: | Phosphate
LOE Subgroup: | Pollutant-Water
Matrix: | Water
Fraction: | Dissolved
Beneficial Use: | Cold Freshwater Habitat
Number of Samples: | 2
Number of Exceedances: | 0
Data and Information Type: | Fixed station physical/chemical (conventional plus toxic pollutants)
Data Used to Assess Water Quality: | The U.S. Geological Survey sampled Mesquite Springs under the Region 6 SWAMP program in 2002 and 2003. Concentrations of phosphate in two samples were 0.013 and 0.018 mg/L. No information on algae growth or other secondary indicators of eutrophication is available to permit evaluation of compliance with the biostimulatory substances objective.
Data Reference: | 2007. SWAMP Data for the Amargosa Hydrologic Unit
SWAMP Data: | SWAMP
Water Quality Objective/Criterion: | There are no site-specific water quality objectives for Mesquite Springs. The Lahontan Basin Plan's narrative objective for biostimulatory substances states: "Waters shall not contain biostimulatory substances in concentrations that promote aquatic growths to the extent that such growths cause nuisance or adversely affect the water for beneficial uses."
Objective/Criterion Reference: | Water Quality Control Plan for the Lahontan Region (as amended)
Evaluation Guideline: |
Guideline Reference:
Spatial Representation: | One station, Mesquite Spring (in Death Valley National Park, near Scottys Castle), was sampled.
Temporal Representation: | Two samples were collected in 2002 and 2003.
Environmental Conditions: | The Mesquite Springs are within the Stovepipe Wells Hydrologic Subarea of the Amargosa Hydrologic Unit (HU No. 609.11). They supply drinking water to a campground. No site-specific water quality objectives apply to the springs. Chemical and radioactive constituents come from natural sources.
QAPP Information: | Data meet the quality assurance requirements of the SWAMP QAPP.
QAPP Information Reference(s):

DECISION ID | 22884 | Region 6
Mesquite Springs (Inyo County)

Pollutant: | Phosphorus
Final Listing Decision: | Do Not List on 303(d) list (TMDL required list)
Last Listing Cycle's Final Listing Decision: | Do Not List on 303(d) list (TMDL required list)(2010)
Revision Status | Original
Impairment from Pollutant or Pollution: | Pollutant
Regional Board Staff Conclusion: | This pollutant was considered for placement on the section 303(d) list in a previous assessment cycle. No new information was reviewed for this current assessment cycle. Therefore, the previous conclusion remains unchanged, and is as follows: This pollutant is being considered for placement on the section 303(d) list under section 3.1 of the Listing Policy. Under section 3.1 a single line of evidence is necessary to assess listing status. One line of evidence is available in the administrative record to assess this pollutant. No biological data are available to assess whether any of the chemical samples exceeds the water quality objective. Based on the readily available data and information, the weight of evidence indicates that there is sufficient justification against placing this water segment-pollutant combination on the section 303(d) list in the Water Quality Limited Segments category. This conclusion is based on the staff findings that: 1. The data used do not satisfy the data quality requirements of section 6.1.4 of the Policy due to an error in the SWAMP QAPP regarding holding times for total phosphorus samples. 2. The data used do not satisfy the data quantity requirements of section 6.1.5 of the Policy in that only one sample per year is available. 3. There are no biological data available for evaluation of compliance with the objective and the data cannot be assessed using Table 3.1 of the Listing Policy. 4. Pursuant to section 3.11 of the Listing Policy, no additional data and information are available indicating that standards are not met.
Regional Board Staff Decision Recommendation: | No new data were assessed for this assessment cycle. The conclusion reached in the previous cycle remains in same. The Regional Board will update this decision when new data and information become available in a future assessment cycle.

Line of Evidence (LOE) for Decision ID 22884, Phosphorus | Region 6
Mesquite Springs (Inyo County)
LOE ID: | 5801
Pollutant: | Phosphorus
LOE Subgroup: | Pollutant-Water
Matrix: | Water
Fraction: | Dissolved
Beneficial Use: | Cold Freshwater Habitat
Number of Samples: | 2
Number of Exceedances: | 0
Data and Information Type: | Fixed station physical/chemical (conventional plus toxic pollutants)
Data Used to Assess Water Quality: | The U.S. Geological Survey sampled Mesquite Springs under the Region 6 SWAMP program in 2002 and 2003. Concentrations of Total Phosphorus in two samples were 0.012 and 0.018 mg/L. No information on algae growth or other secondary indicators of eutrophication is available to permit evaluation of compliance with the biostimulatory substances objective.
Data Reference: | 2007. SWAMP Data for the Amargosa Hydrologic Unit
SWAMP Data: | SWAMP
Water Quality Objective/Criterion: | There are no site-specific water quality objectives for Mesquite Springs. The Lahontan Basin Plan's narrative objective for biostimulatory substances states: "Waters shall not contain biostimulatory substances in concentrations that promote aquatic growths to the extent that such growths cause nuisance or adversely affect the water for beneficial uses."
Objective/Criterion Reference: | Water Quality Control Plan for the Lahontan Region (as amended)
Evaluation Guideline: |
Guideline Reference:
Spatial Representation: | One station, Mesquite Spring (in Death Valley National Park, near Scottys Castle), was sampled.
Temporal Representation: | Two samples were collected in 2002 and 2003.
Environmental Conditions: | The Mesquite Springs are within the Stovepipe Wells Hydrologic Subarea of the Amargosa Hydrologic Unit (HU No. 609.11). They supply drinking water to a campground. No site-specific water quality objectives apply to the springs. Chemical and radioactive constituents come from natural sources.
QAPP Information: | Sampling and analysis were done according to the SWAMP QAPP. However, in July 2009 an error was discovered in the QAPP related to holding times for total phosphorus samples that affects the validity of data for the Lahontan Region The holding time for samples that are not acid-preserved.should be 48 hours rather than 28 days as indicated in the QAPP. "Low level" phosphorus analyses, without acid preservation, are used in the Lahontan Region's SWAMP program. ..
QAPP Information Reference(s):

DECISION ID | 23444 | Region 6
Mesquite Springs (Inyo County)

Pollutant: | Potassium
Final Listing Decision: | Do Not List on 303(d) list (TMDL required list)
Last Listing Cycle's Final Listing Decision: | Do Not List on 303(d) list (TMDL required list)(2010)
Revision Status | Original
Impairment from Pollutant or Pollution: | Pollutant
Regional Board Staff Conclusion: | This pollutant was considered for placement on the section 303(d) list in a previous assessment cycle. No new information was reviewed for this current assessment cycle. Therefore, the previous conclusion remains unchanged, and is as follows: This pollutant is being considered for placement on the section 303(d) list under section 3.2 of the Listing Policy. Under section 3.2 a single line of evidence is necessary to assess listing status. One line of evidence is available in the administrative record to assess this pollutant. There are no applicable state or federal standards or criteria for potassium. Based on the readily available data and information, the weight of evidence indicates that there is sufficient justification against placing this water segment-pollutant combination on the section 303(d) list in the Water Quality Limited Segments category. This conclusion is based on the staff findings that: 1. The data used satisfy the data quality requirements of section 6.1.4 of the Policy. 2. The data used do not satisfy the data quantity requirements of section 6.1.5 of the Policy. 3. There are no applicable water quality standards or criteria and the data cannot be assessed using Table 3.2 of the Listing Policy. 4. Pursuant to section 3.11 of the Listing Policy, no additional data and information are available indicating that standards are not met.
Regional Board Staff Decision Recommendation: | No new data were assessed for this assessment cycle. The conclusion reached in the previous cycle remains in same. The Regional Board will update this decision when new data and information become available in a future assessment cycle.

Line of Evidence (LOE) for Decision ID 23444, Potassium | Region 6
Mesquite Springs (Inyo County)
LOE ID: | 21255
Pollutant: | Potassium
LOE Subgroup: | Pollutant-Water
Matrix: | Water
Fraction: | Dissolved
Beneficial Use: | Cold Freshwater Habitat
Number of Samples: | 2
Number of Exceedances: | 0
Data and Information Type: | Fixed station physical/chemical (conventional plus toxic pollutants)
Data Used to Assess Water Quality: | The U.S. Geological Survey sampled Mesquite Springs under the Region 6 SWAMP program in 2002 and 2003. The concentrations of dissolved potassium in two samples were 13.4 and 7.8 mg/L.
Data Reference: | 2007. SWAMP Data for the Amargosa Hydrologic Unit
SWAMP Data: | SWAMP
Water Quality Objective/Criterion: | There are no state or federal standards, water quality objectives or criteria for potassium.
Objective/Criterion Reference: | Water Quality Control Plan for the Lahontan Region (as amended)
Evaluation Guideline: |
Guideline Reference:
Spatial Representation: | One station, Mesquite Spring (in Death Valley National Park, near Scottys Castle), was sampled.
Temporal Representation: | Two samples were collected in 2002 and 2003.
Environmental Conditions: | The Mesquite Springs are within the Stovepipe Wells Hydrologic Subarea of the Amargosa Hydrologic Unit (HU No. 609.11). They supply drinking water to a campground. No site-specific water quality objectives apply to the springs. Chemical and radioactive constituents come from natural sources.
QAPP Information: | Data meet the quality assurance requirements of the SWAMP QAPP.
QAPP Information Reference(s):

DECISION ID | 20751 | Region 6
Mesquite Springs (Inyo County)

Pollutant: | Selenium
Final Listing Decision: | Do Not List on 303(d) list (TMDL required list)
Last Listing Cycle's Final Listing Decision: | Do Not List on 303(d) list (TMDL required list)(2010)
Revision Status | Original
Impairment from Pollutant or Pollution: | Pollutant
Regional Board Staff Conclusion: | This pollutant was considered for placement on the section 303(d) list in a previous assessment cycle. No new information was reviewed for this current assessment cycle. Therefore, the previous conclusion remains unchanged, and is as follows: This pollutant is being considered for placement on the section 303(d) list under section 3.1 of the Listing Policy. Under section 3.1 a single line of evidence is necessary to assess listing status. Two lines of evidence are available in the administrative record to assess this pollutant. Neither of the samples exceeds the California Toxics Rule standard or the California Maximum Contaminant Level. Based on the readily available data and information, the weight of evidence indicates that there is sufficient justification against placing this water segment-pollutant combination on the section 303(d) list in the Water Quality Limited Segments category. This conclusion is based on the staff findings that: 1. The data used satisfy the data quality requirements of section 6.1.4 of the Policy. 2. The data used do satisfy the data quantity requirements of section 6.1.5 of the Policy in that only one sample per year is available. 3. Neither of two samples exceeded the applicable standards and this does not exceed the allowable frequency listed in Table 3.1 of the Listing Policy. 4. Pursuant to section 3.11 of the Listing Policy, no additional data and information are available indicating that standards are not met.
Regional Board Staff Decision Recommendation: | No new data were assessed for this assessment cycle. The conclusion reached in the previous cycle remains in same. The Regional Board will update this decision when new data and information become available in a future assessment cycle.

Line of Evidence (LOE) for Decision ID 20751, Selenium | Region 6
Mesquite Springs (Inyo County)
LOE ID: | 5317
Pollutant: | Selenium
LOE Subgroup: | Pollutant-Water
Matrix: | Water
Fraction: | Dissolved
Beneficial Use: | Cold Freshwater Habitat
Number of Samples: | 2
Number of Exceedances: | 0
Data and Information Type: | Fixed station physical/chemical (conventional plus toxic pollutants)
Data Used to Assess Water Quality: | The U.S. Geological Survey sampled Mesquite Springs under the Region 6 SWAMP program in 2002 and 2003. Dissolved selenium concentrations in two samples were 1.5 and 1.4 ug/L.The CTR standard was not exceeded.
Data Reference: | 2007. SWAMP Data for the Amargosa Hydrologic Unit
SWAMP Data: | SWAMP
Water Quality Objective/Criterion: | The California Toxics Rule (CTR) 4 -day average aquatic life standard for selenium is 5 ug/L.
Objective/Criterion Reference: | Water Quality Standards 2000. Establishment of numeric criteria for priority toxic pollutants for the State of California: Rules and regulations. Federal Register Vol. 65, No. 97. Washington, D.C.: Environmental Protection Agency
Evaluation Guideline: |
Guideline Reference:
Spatial Representation: | One station, Mesquite Spring (in Death Valley National Park, near Scottys Castle), was sampled.
Temporal Representation: | Two samples were collected in 2002 and 2003.
Environmental Conditions: | The Mesquite Springs are within the Stovepipe Wells Hydrologic Subarea of the Amargosa Hydrologic Unit (HU No. 609.11). They supply drinking water to a campground. No site-specific water quality objectives apply to the springs. Chemical and radioactive constituents come from natural sources.
QAPP Information: | Data meet the quality assurance requirements of the SWAMP QAPP.
QAPP Information Reference(s):
Line of Evidence (LOE) for Decision ID 20751, Selenium | Region 6
Mesquite Springs (Inyo County)
LOE ID: | 5316
Pollutant: | Selenium
LOE Subgroup: | Pollutant-Water
Matrix: | Water
Fraction: | Dissolved
Beneficial Use: | Municipal & Domestic Supply
Number of Samples: | 2
Number of Exceedances: | 0
Data and Information Type: | Fixed station physical/chemical (conventional plus toxic pollutants)
Data Used to Assess Water Quality: | The U.S. Geological Survey sampled Mesquite Springs under the Region 6 SWAMP program in 2002 and 2003. Dissolved selenium concentrations in two samples were 1.5 and 1.4 ug/L.The MCL was not exceeded.
Data Reference: | 2007. SWAMP Data for the Amargosa Hydrologic Unit
SWAMP Data: | SWAMP
Water Quality Objective/Criterion: | California Maximum Contaminant Levels (MCLs) apply to ambient waters under the Lahontan Basin Plan's "Chemical Constituents" objective. The MCL for selenium is 50 ug/L. \
Objective/Criterion Reference: | Water Quality Control Plan for the Lahontan Region (as amended)
Evaluation Guideline: |
Guideline Reference:
Spatial Representation: | One station, Mesquite Spring (in Death Valley National Park, near Scottys Castle), was sampled.
Temporal Representation: | Two samples were collected in 2002 and 2003.
Environmental Conditions: | The Mesquite Springs are within the Stovepipe Wells Hydrologic Subarea of the Amargosa Hydrologic Unit (HU No. 609.11). They supply drinking water to a campground. No site-specific water quality objectives apply to the springs. Chemical and radioactive constituents come from natural sources.
QAPP Information: | Data meet the quality assurance requirements of the SWAMP QAPP.
QAPP Information Reference(s):

DECISION ID | 20875 | Region 6
Mesquite Springs (Inyo County)

Pollutant: | Silica
Final Listing Decision: | Do Not List on 303(d) list (TMDL required list)
Last Listing Cycle's Final Listing Decision: | Do Not List on 303(d) list (TMDL required list)(2010)
Revision Status | Original
Impairment from Pollutant or Pollution: | Pollutant
Regional Board Staff Conclusion: | This pollutant was considered for placement on the section 303(d) list in a previous assessment cycle. No new information was reviewed for this current assessment cycle. Therefore, the previous conclusion remains unchanged, and is as follows: This pollutant is being considered for placement on the section 303(d) list under section 3.2 of the Listing Policy. Under section 3.2 a single line of evidence is necessary to assess listing status. One line of evidence is available in the administrative record to assess this analyte. RWQCB staff are not aware of any water quality standards, criteria, or guidelines for silica (silicon dioxide). Silica is a naturally occurring substance that is essential for some aquatic organisms (i.e., diatoms). Only two samples are available, and this number is insufficient for assessment using listing policy Table 3.2. Based on the readily available data and information, the weight of evidence indicates that there is sufficient justification against placing this water segment-pollutant combination on the section 303(d) list in the Water Quality Limited Segments category.
Regional Board Staff Decision Recommendation: | No new data were assessed for this assessment cycle. The conclusion reached in the previous cycle remains in same. The Regional Board will update this decision when new data and information become available in a future assessment cycle.

Line of Evidence (LOE) for Decision ID 20875, Silica | Region 6
Mesquite Springs (Inyo County)
LOE ID: | 5805
Pollutant: | Silica
LOE Subgroup: | Pollutant-Water
Matrix: | Water
Fraction: | Dissolved
Beneficial Use: | Cold Freshwater Habitat
Number of Samples: | 2
Number of Exceedances: | 0
Data and Information Type: | Fixed station physical/chemical (conventional plus toxic pollutants)
Data Used to Assess Water Quality: | The U.S. Geological Survey sampled Mesquite Springs under the Region 6 SWAMP program in 2002 and 2003. Concentrations of dissolved silica in two samples were 69.9 and 67 mg/L. If standards or criteria were available, these sample numbers would be too small for assessment with Listing Policy Table 3-2.
Data Reference: | 2007. SWAMP Data for the Amargosa Hydrologic Unit
SWAMP Data: | SWAMP
Water Quality Objective/Criterion: | There are no California or federal standards or criteria for silica (silicon dioxide) It is sometimes monitored because of its importance as a structural material in the cell walls of diatoms.
Objective/Criterion Reference: | Water Quality Control Plan for the Lahontan Region (as amended)
Evaluation Guideline: |
Guideline Reference:
Spatial Representation: | One station, Mesquite Spring (in Death Valley National Park, near Scottys Castle), was sampled.
Temporal Representation: | Two samples were collected in 2002 and 2003.
Environmental Conditions: | The Mesquite Springs are within the Stovepipe Wells Hydrologic Subarea of the Amargosa Hydrologic Unit (HU No. 609.11). They supply drinking water to a campground. No site-specific water quality objectives apply to the springs. Chemical and radioactive constituents come from natural sources.
QAPP Information: | Data meet the quality assurance requirements of the SWAMP QAPP.
QAPP Information Reference(s):

DECISION ID | 23234 | Region 6
Mesquite Springs (Inyo County)

Pollutant: | Sodium
Final Listing Decision: | Do Not List on 303(d) list (TMDL required list)
Last Listing Cycle's Final Listing Decision: | Do Not List on 303(d) list (TMDL required list)(2010)
Revision Status | Original
Impairment from Pollutant or Pollution: | Pollutant
Regional Board Staff Conclusion: | This pollutant was considered for placement on the section 303(d) list in a previous assessment cycle. No new information was reviewed for this current assessment cycle. Therefore, the previous conclusion remains unchanged, and is as follows: This pollutant is being considered for placement on the section 303(d) list under section 3.2 of the Listing Policy. Under section 3.2 a single line of evidence is necessary to assess listing status. Two line(s) of evidence is available in the administrative record to assess this pollutant. There are no applicable standards or criteria for sodium for the protection of freshwater aquatic life. Two of the samples exceed the U.S. Environmental Protection Agency (USEPA) drinking water advisory level criterion. USEPA guidance states that the criterion is non-regulatory and that it applies to persons who must restrict their daily intake of sodium and should not be extrapolated to the general population. Based on the readily available data and information, the weight of evidence indicates that there is sufficient justification against placing this water segment-pollutant combination on the section 303(d) list in the Water Quality Limited Segments category. This conclusion is based on the staff findings that: 1. The data used satisfy the data quality requirements of section 6.1.4 of the Policy. 2. The data used do not satisfy the data quantity requirements of section 6.1.5 of the Policy. 3. Two of two samples exceeded the USEPA drinking water health advisory criterion and this does not exceed the allowable frequency listed in Table 3.2 of the Listing Policy. 4. Pursuant to section 3.11 of the Listing Policy, no additional data and information are available indicating that standards are not met.
Regional Board Staff Decision Recommendation: | No new data were assessed for this assessment cycle. The conclusion reached in the previous cycle remains in same. The Regional Board will update this decision when new data and information become available in a future assessment cycle.

Line of Evidence (LOE) for Decision ID 23234, Sodium | Region 6
Mesquite Springs (Inyo County)
LOE ID: | 21264
Pollutant: | Sodium
LOE Subgroup: | Pollutant-Water
Matrix: | Water
Fraction: | Dissolved
Beneficial Use: | Municipal & Domestic Supply
Number of Samples: | 2
Number of Exceedances: | 2
Data and Information Type: | Fixed station physical/chemical (conventional plus toxic pollutants)
Data Used to Assess Water Quality: | The U.S. Geological Survey sampled Mesquite Springs under the Region 6 SWAMP program in 2002 and 2003. The concentrations of dissolved sodium in two samples were 230 and 221 mg/L.
Data Reference: | 2007. SWAMP Data for the Amargosa Hydrologic Unit
SWAMP Data: | SWAMP
Water Quality Objective/Criterion: | The U.S. Environmental Protection Agency's Drinking Water Health Advisory criterion for sodium is 20 mg/L.
Objective/Criterion Reference: | Drinking Water Advisory: Consumer Acceptability Advice and Health Effects Analysis
Evaluation Guideline: |
Guideline Reference:
Spatial Representation: | One station, Mesquite Spring (in Death Valley National Park, near Scottys Castle), was sampled.
Temporal Representation: | Two samples were collected in 2002 and 2003.
Environmental Conditions: | The Mesquite Springs are within the Stovepipe Wells Hydrologic Subarea of the Amargosa Hydrologic Unit (HU No. 609.11). They supply drinking water to a campground. No site-specific water quality objectives apply to the springs. Chemical and radioactive constituents come from natural sources.
QAPP Information: | Data meet the quality assurance requirements of the SWAMP QAPP.
QAPP Information Reference(s):
Line of Evidence (LOE) for Decision ID 23234, Sodium | Region 6
Mesquite Springs (Inyo County)
LOE ID: | 21260
Pollutant: | Sodium
LOE Subgroup: | Pollutant-Water
Matrix: | Water
Fraction: | Dissolved
Beneficial Use: | Cold Freshwater Habitat
Number of Samples: | 2
Number of Exceedances: | 0
Data and Information Type: | Fixed station physical/chemical (conventional plus toxic pollutants)
Data Used to Assess Water Quality: | The U.S. Geological Survey sampled Mesquite Springs under the Region 6 SWAMP program in 2002 and 2003. The concentrations of dissolved sodium in two samples were 230 and 221 mg/L.
Data Reference: | 2007. SWAMP Data for the Amargosa Hydrologic Unit
SWAMP Data: | SWAMP
Water Quality Objective/Criterion: | There are no state or federal standards, water quality objectives or criteria for sodium for protection of aquatic life.
Objective/Criterion Reference: | Water Quality Control Plan for the Lahontan Region (as amended)
Evaluation Guideline: |
Guideline Reference:
Spatial Representation: | One station, Mesquite Spring (in Death Valley National Park, near Scottys Castle), was sampled.
Temporal Representation: | Two samples were collected in 2002 and 2003.
Environmental Conditions: | The Mesquite Springs are within the Stovepipe Wells Hydrologic Subarea of the Amargosa Hydrologic Unit (HU No. 609.11). They supply drinking water to a campground. No site-specific water quality objectives apply to the springs. Chemical and radioactive constituents come from natural sources.
QAPP Information: | Data meet the quality assurance requirements of the SWAMP QAPP.
QAPP Information Reference(s):

DECISION ID | 20753 | Region 6
Mesquite Springs (Inyo County)

Pollutant: | Specific Conductance
Final Listing Decision: | Do Not List on 303(d) list (TMDL required list)
Last Listing Cycle's Final Listing Decision: | Do Not List on 303(d) list (TMDL required list)(2010)
Revision Status | Original
Impairment from Pollutant or Pollution: | Pollutant
Regional Board Staff Conclusion: | This pollutant was considered for placement on the section 303(d) list in a previous assessment cycle. No new information was reviewed for this current assessment cycle. Therefore, the previous conclusion remains unchanged, and is as follows: This pollutant is being considered for placement on the section 303(d) list under section 3.2 of the Listing Policy. Under section 3.2 a single line of evidence is necessary to assess listing status. One line of evidence is available in the administrative record to assess this pollutant. None of the samples exceeds the upper limit in the California Maximum Contaminant Level (MCL). Based on the readily available data and information, the weight of evidence indicates that there is sufficient justification against placing this water segment-pollutant combination on the section 303(d) list in the Water Quality Limited Segments category. This conclusion is based on the staff findings that: 1. The data used satisfy the data quality requirements of section 6.1.4 of the Policy. 2. The data (one field measurement and two laboratory measurements taken over two years, are not temporally representative as required by section 6.1.5 of the Policy. 3. The single field measurement and two laboratory measurements did not exceed the MCL and this does not exceed the allowable frequency listed in Table 3.2 of the Listing Policy. However, the minimum sample number requirements of Table 3.2 were not met. 4. Pursuant to section 3.11 of the Listing Policy, no additional data and information are available indicating that standards are not met.
Regional Board Staff Decision Recommendation: | No new data were assessed for this assessment cycle. The conclusion reached in the previous cycle remains in same. The Regional Board will update this decision when new data and information become available in a future assessment cycle.

Line of Evidence (LOE) for Decision ID 20753, Specific Conductance | Region 6
Mesquite Springs (Inyo County)
LOE ID: | 5249
Pollutant: | Specific Conductance
LOE Subgroup: | Pollutant-Water
Matrix: | Water
Fraction: | Dissolved
Beneficial Use: | Municipal & Domestic Supply
Number of Samples: | 1
Number of Exceedances: | 0
Data and Information Type: | Not Specified
Data Used to Assess Water Quality: | The U.S. Geological Survey sampled Mesquite Springs under the Region 6 SWAMP program.Two laboratory specific conductance measurements were, 1240 and 1150 uS/cm, and one field measurement was 1250 uS/cm. The recommended MCL was exceeded, but the upper limit was not. Sample numbers were too small for use with the Listing Policy's binomial model.
Data Reference: | 2007. SWAMP Data for the Amargosa Hydrologic Unit
SWAMP Data: | SWAMP
Water Quality Objective/Criterion: | California Maximum Contaminant Levels (MCLs) apply to ambient waters under the Lahontan Basin Plan's "Chemical Constituents" objective. The recommended MCL for specific conductance is 900 microsiemens per centimeter (uS/cm). The MCL includes an upper limit of 1600 uS/cm, and a short term limit of 2200 uS/cm.
Objective/Criterion Reference: | Water Quality Control Plan for the Lahontan Region (as amended)
Evaluation Guideline: |
Guideline Reference:
Spatial Representation: | One station, Mesquite Spring (in Death Valley National Park, near Scottys Castle), was sampled.
Temporal Representation: | Two laboratory measurements and one field measurement were taken in 2002 and 2003.
Environmental Conditions: | The Mesquite Springs are within the Stovepipe Wells Hydrologic Subarea of the Amargosa Hydrologic Unit (HU No. 609.11). They supply drinking water to a campground. No site-specific water quality objectives apply to the springs. Chemical and radioactive constituents, including the salts that contribute to high specific conductance levels, come from natural sources.
QAPP Information: | Data meet the quality assurance requirements of the SWAMP QAPP.
QAPP Information Reference(s):

DECISION ID | 23197 | Region 6
Mesquite Springs (Inyo County)

Pollutant: | Strontium
Final Listing Decision: | Do Not List on 303(d) list (TMDL required list)
Last Listing Cycle's Final Listing Decision: | Do Not List on 303(d) list (TMDL required list)(2010)
Revision Status | Original
Impairment from Pollutant or Pollution: | Pollutant
Regional Board Staff Conclusion: | This pollutant was considered for placement on the section 303(d) list in a previous assessment cycle. No new information was reviewed for this current assessment cycle. Therefore, the previous conclusion remains unchanged, and is as follows: This pollutant is being considered for placement on the section 303(d) list under section 3.1 of the Listing Policy. Under section 3.1 a single line of evidence is necessary to assess listing status. One line of evidence is available in the administrative record to assess this pollutant. None of the samples exceeds the applicable water quality criterion. Based on the readily available data and information, the weight of evidence indicates that there is sufficient justification against placing this water segment-pollutant combination on the section 303(d) list in the Water Quality Limited Segments category. This conclusion is based on the staff findings that: 1. The data used satisfy the data quality requirements of section 6.1.4 of the Policy. 2. The data used do not satisfy the data quantity requirements of section 6.1.5 of the Policy in that only one sample per year is available. 3. Neither of two samples exceeded the water quality criterion and this does not exceed the allowable frequency listed in Table 3.1 of the Listing Policy. 4. Pursuant to section 3.11 of the Listing Policy, no additional data and information are available indicating that standards are not met.
Regional Board Staff Decision Recommendation: | No new data were assessed for this assessment cycle. The conclusion reached in the previous cycle remains in same. The Regional Board will update this decision when new data and information become available in a future assessment cycle.

Line of Evidence (LOE) for Decision ID 23197, Strontium | Region 6
Mesquite Springs (Inyo County)
LOE ID: | 21286
Pollutant: | Strontium
LOE Subgroup: | Pollutant-Water
Matrix: | Water
Fraction: | Dissolved
Beneficial Use: | Municipal & Domestic Supply
Number of Samples: | 2
Number of Exceedances: | 0
Data and Information Type: | Fixed station physical/chemical (conventional plus toxic pollutants)
Data Used to Assess Water Quality: | The U.S. Geological Survey sampled Mesquite Springs under the Region 6 SWAMP program in 2002 and 2003. The reported concentrations of dissolved strontium in 2 samples were 320 and 344 ug/L. The criterion was not exceeded.
Data Reference: | 2007. SWAMP Data for the Amargosa Hydrologic Unit
SWAMP Data: | SWAMP
Water Quality Objective/Criterion: | The U.S. Environmental Protection Agency's Significant No Adverse Risk Level (SNARL) criterion for strontium is 4000 ug/L.
Objective/Criterion Reference: | Water Quality Control Plan for the Lahontan Region (as amended)
Evaluation Guideline: |
Guideline Reference:
Spatial Representation: | One station, Mesquite Spring (in Death Valley National Park, near Scottys Castle), was sampled.
Temporal Representation: | Two samples were collected in 2002 and 2003.
Environmental Conditions: | The Mesquite Springs are within the Stovepipe Wells Hydrologic Subarea of the Amargosa Hydrologic Unit (HU No. 609.11). They supply drinking water to a campground. No site-specific water quality objectives apply to the springs. Chemical and radioactive constituents come from natural sources.
QAPP Information: | Data meet the quality assurance requirements of the SWAMP QAPP.
QAPP Information Reference(s):

DECISION ID | 23376 | Region 6
Mesquite Springs (Inyo County)

Pollutant: | Strontium 87/Strontium 86 ratio
Final Listing Decision: | Do Not List on 303(d) list (TMDL required list)
Last Listing Cycle's Final Listing Decision: | Do Not List on 303(d) list (TMDL required list)(2010)
Revision Status | Original
Impairment from Pollutant or Pollution: | Pollutant
Regional Board Staff Conclusion: | This pollutant was considered for placement on the section 303(d) list in a previous assessment cycle. No new information was reviewed for this current assessment cycle. Therefore, the previous conclusion remains unchanged, and is as follows: This pollutant is being considered for placement on the section 303(d) list under section 3.1 of the Listing Policy. Under section 3.1 a single line of evidence is necessary to assess listing status. Two lines of evidence are available in the administrative record to assess this pollutant. There are no California or federal criteria, standards, or water quality objectives applicable to strontium 86/strontium 87 ratio. Based on the readily available data and information, the weight of evidence indicates that there is sufficient justification against placing this water segment-pollutant combination on the section 303(d) list in the Water Quality Limited Segments category.
Regional Board Staff Decision Recommendation: | No new data were assessed for this assessment cycle. The conclusion reached in the previous cycle remains in same. The Regional Board will update this decision when new data and information become available in a future assessment cycle.

Line of Evidence (LOE) for Decision ID 23376, Strontium 87/Strontium 86 ratio | Region 6
Mesquite Springs (Inyo County)
LOE ID: | 21280
Pollutant: | Strontium 87/Strontium 86 ratio
LOE Subgroup: | Pollutant-Water
Matrix: | Water
Fraction: | Dissolved
Beneficial Use: | Cold Freshwater Habitat
Number of Samples: | 2
Number of Exceedances: | 0
Data and Information Type: | Fixed station physical/chemical (conventional plus toxic pollutants)
Data Used to Assess Water Quality: | The U.S. Geological Survey sampled Mesquite Springs under the Region 6 SWAMP program in 2002 and 2003. The reported strontium 87/strontium 86 ratios in two samples (as ml) were 0.71112 and 0.71116.
Data Reference: | 2007. SWAMP Data for the Amargosa Hydrologic Unit
SWAMP Data: | SWAMP
Water Quality Objective/Criterion: | There are no state or federal standards, water quality objectives or criteria for strontium 87/strontium 86 ratio..
Objective/Criterion Reference: | Water Quality Control Plan for the Lahontan Region (as amended)
Evaluation Guideline: |
Guideline Reference:
Spatial Representation: | One station, Mesquite Spring (in Death Valley National Park, near Scottys Castle), was sampled.
Temporal Representation: | Two samples were collected in 2002 and 2003.
Environmental Conditions: | The Mesquite Springs are within the Stovepipe Wells Hydrologic Subarea of the Amargosa Hydrologic Unit (HU No. 609.11). They supply drinking water to a campground. No site-specific water quality objectives apply to the springs. Chemical and radioactive constituents come from natural sources.
QAPP Information: | Data meet the quality assurance requirements of the SWAMP QAPP.
QAPP Information Reference(s):

DECISION ID | 23359 | Region 6
Mesquite Springs (Inyo County)

Pollutant: | Sulfates
Final Listing Decision: | Do Not List on 303(d) list (TMDL required list)
Last Listing Cycle's Final Listing Decision: | Do Not List on 303(d) list (TMDL required list)(2010)
Revision Status | Original
Impairment from Pollutant or Pollution: | Pollutant
Regional Board Staff Conclusion: | This pollutant was considered for placement on the section 303(d) list in a previous assessment cycle. No new information was reviewed for this current assessment cycle. Therefore, the previous conclusion remains unchanged, and is as follows: This pollutant is being considered for placement on the section 303(d) list under section 3.2 of the Listing Policy. Under section 3.2 a single line of evidence is necessary to assess listing status. One line of evidence is available in the administrative record to assess this pollutant. Neither of the samples exceeds the California Maximum Contaminant Level (MCL). Based on the readily available data and information, the weight of evidence indicates that there is sufficient justification against placing this water segment-pollutant combination on the section 303(d) list in the Water Quality Limited Segments category. This conclusion is based on the staff findings that: 1. The data used satisfy the data quality requirements of section 6.1.4 of the Policy. 2. The data used do not satisfy the data quantity requirements of section 6.1.5 of the Policy in that only one sample per year is available. 3. Neither of two samples exceeded the MCL and this does not exceed the allowable frequency listed in Table 3.2 of the Listing Policy. However, the minimum sample number requirements of Table 3.2 are not met. 4. Pursuant to section 3.11 of the Listing Policy, no additional data and information are available indicating that standards are not met.
Regional Board Staff Decision Recommendation: | No new data were assessed for this assessment cycle. The conclusion reached in the previous cycle remains in same. The Regional Board will update this decision when new data and information become available in a future assessment cycle.

Line of Evidence (LOE) for Decision ID 23359, Sulfates | Region 6
Mesquite Springs (Inyo County)
LOE ID: | 5253
Pollutant: | Sulfates
LOE Subgroup: | Pollutant-Water
Matrix: | Water
Fraction: | Dissolved
Beneficial Use: | Municipal & Domestic Supply
Number of Samples: | 2
Number of Exceedances: | 0
Data and Information Type: | Not Specified
Data Used to Assess Water Quality: | The U.S. Geological Survey sampled Mesquite Springs under the Region 6 SWAMP program. Sulfate concentrations in two samples were 174 and 172 mg/L.. The MCL was not exceeded, but sample numbers were too small for use with the Listing Policy's binomial model.
Data Reference: | 2007. SWAMP Data for the Amargosa Hydrologic Unit
SWAMP Data: | SWAMP
Water Quality Objective/Criterion: | California Maximum Contaminant Levels (MCLs) apply to ambient waters under the Lahontan Basin Plan's "Chemical Constituents" objective. The MCL for sulfate is 250 mg/L.
Objective/Criterion Reference: | Water Quality Control Plan for the Lahontan Region (as amended)
Evaluation Guideline: |
Guideline Reference:
Spatial Representation: | One station, Mesquite Spring (in Death Valley National Park, near Scottys Castle), was sampled.
Temporal Representation: | Two samples were collected in 2002 and 2003.
Environmental Conditions: | The Mesquite Springs are within the Stovepipe Wells Hydrologic Subarea of the Amargosa Hydrologic Unit (HU No. 609.11). They supply drinking water to a campground. No site-specific water quality objectives apply to the springs. Chemical and radioactive constituents come from natural sources.
QAPP Information: | Data meet the quality assurance requirements of the SWAMP QAPP.
QAPP Information Reference(s):

DECISION ID | 20780 | Region 6
Mesquite Springs (Inyo County)

Pollutant: | Temperature, water
Final Listing Decision: | Do Not List on 303(d) list (TMDL required list)
Last Listing Cycle's Final Listing Decision: | Do Not List on 303(d) list (TMDL required list)(2010)
Revision Status | Original
Impairment from Pollutant or Pollution: | Pollutant
Regional Board Staff Conclusion: | This pollutant was considered for placement on the section 303(d) list in a previous assessment cycle. No new information was reviewed for this current assessment cycle. Therefore, the previous conclusion remains unchanged, and is as follows: The Lahontan Basin Plan's narrative temperature objective is an antidegradation-based objective that requires that there be no change in temperature in waters designated for the Cold Freshwater Habitat (COLD) beneficial use. The objective does not include specific numerical limits for protection of the COLD use. Listing Policy Section 3.10 contains directions for assessment based on trends in water quality. These directions include requirements to establish specific baseline conditions and specify the influence of seasonal and interannual effects. One line of evidence is available to support this decision. There are not enough temperature samples to establish baseline conditions (including diel, seasonal, annual and interannual variations in temperature) or to detect declining trends in the temperature regime if such trends exist.
Regional Board Staff Decision Recommendation: | No new data were assessed for this assessment cycle. The conclusion reached in the previous cycle remains in same. The Regional Board will update this decision when new data and information become available in a future assessment cycle.

Line of Evidence (LOE) for Decision ID 20780, Temperature, water | Region 6
Mesquite Springs (Inyo County)
LOE ID: | 5259
Pollutant: | Temperature, water
LOE Subgroup: | Pollutant-Water
Matrix: | Water
Fraction: | None
Beneficial Use: | Cold Freshwater Habitat
Number of Samples: | 2
Number of Exceedances: | 0
Data and Information Type: | Fixed station physical/chemical (conventional plus toxic pollutants)
Data Used to Assess Water Quality: | The U.S. Geological Survey sampled Mesquite Springs under the Region 6 SWAMP program. Two temperature measurements, were 25 and 22 degrees Celsius. Sampling frequency was inadequate to define the natural temperature regime or to determine whether changes have occurred.
Data Reference: | 2007. SWAMP Data for the Amargosa Hydrologic Unit
SWAMP Data: | SWAMP
Water Quality Objective/Criterion: | The Lahontan Basin Plan's objective for temperature states: Objective: "The natural receiving water temperature of all waters shall not be altered unless it can be demonstrated to the satisfaction of the Regional Board that such an alteration in temperature does not adversely affect the water for beneficial uses. For waters designated WARM, water temperature shall not be altered by more than five degrees Fahrenheit ... above or below the natural temperature. For waters designated COLD, the temperature shall not be altered."
Objective/Criterion Reference: | Water Quality Control Plan for the Lahontan Region (as amended)
Evaluation Guideline: |
Guideline Reference:
Spatial Representation: | One station, Mesquite Spring (in Death Valley National Park, near Scottys Castle), was sampled.
Temporal Representation: | Two measurements of water temperature were taken in 2002 and 2003. Sampling frequency was inadequate to define the natural temperature regime or to determine whether changes have occurred.
Environmental Conditions: | The Mesquite Springs are within the Stovepipe Wells Hydrologic Subarea of the Amargosa Hydrologic Unit (HU No. 609.11). They supply drinking water to a campground. No site-specific water quality objectives apply to the springs. Chemical and radioactive constituents, including the salts that contribute to high specific conductance levels, come from natural sources. The Mesquite Springs are designated for both the Warm Freshwater Habitat and Cold Freshwater Habitat beneficial uses, and for the Rare, Threatened or Endangered Species Use. These springs do not support salmonid fish, and temperature criteria for salmonids are not relevant for this assessment.
QAPP Information: | Data meet the quality assurance requirements of the SWAMP QAPP.
QAPP Information Reference(s):

DECISION ID | 23496 | Region 6
Mesquite Springs (Inyo County)

Pollutant: | Titanium
Final Listing Decision: | Do Not List on 303(d) list (TMDL required list)
Last Listing Cycle's Final Listing Decision: | Do Not List on 303(d) list (TMDL required list)(2010)
Revision Status | Original
Impairment from Pollutant or Pollution: | Pollutant
Regional Board Staff Conclusion: | This pollutant was considered for placement on the section 303(d) list in a previous assessment cycle. No new information was reviewed for this current assessment cycle. Therefore, the previous conclusion remains unchanged, and is as follows: This pollutant is being considered for placement on the section 303(d) list under section 3.1 of the Listing Policy. Under section 3.1 a single line of evidence is necessary to assess listing status. Two lines of evidence are available in the administrative record to assess this pollutant. There are no California or federal criteria, standards, or water quality objectives applicable to titanium. Based on the readily available data and information, the weight of evidence indicates that there is sufficient justification against placing this water segment-pollutant combination on the section 303(d) list in the Water Quality Limited Segments category.
Regional Board Staff Decision Recommendation: | No new data were assessed for this assessment cycle. The conclusion reached in the previous cycle remains in same. The Regional Board will update this decision when new data and information become available in a future assessment cycle.

Line of Evidence (LOE) for Decision ID 23496, Titanium | Region 6
Mesquite Springs (Inyo County)
LOE ID: | 6227
Pollutant: | Titanium
LOE Subgroup: | Pollutant-Water
Matrix: | Water
Fraction: | Dissolved
Beneficial Use: | Municipal & Domestic Supply
Number of Samples: | 2
Number of Exceedances: | 0
Data and Information Type: | Fixed station physical/chemical (conventional plus toxic pollutants)
Data Used to Assess Water Quality: | The U.S. Geological Survey sampled Mesquite Springs under the Region 6 SWAMP program in 2002 and 2003. A radioactive isotope of titanium was measured. Two samples had activities of -0.2 and 0.1 picocuries per liter (pCi/L).
Data Reference: | 2007. SWAMP Data for the Amargosa Hydrologic Unit
SWAMP Data: | SWAMP
Water Quality Objective/Criterion: | There are no state or federal water quality standards or criteria for titanium.
Objective/Criterion Reference: | Water Quality Control Plan for the Lahontan Region (as amended)
Evaluation Guideline: |
Guideline Reference:
Spatial Representation: | One station, Mesquite Spring (in Death Valley National Park, near Scottys Castle), was sampled.
Temporal Representation: | Two samples were collected in 2002 and 2003.
Environmental Conditions: | The Mesquite Springs are within the Stovepipe Wells Hydrologic Subarea of the Amargosa Hydrologic Unit (HU No. 609.11). They supply drinking water to a campground. No site-specific water quality objectives apply to the springs. Chemical and radioactive constituents come from natural sources.
QAPP Information: | Data meet the quality assurance requirements of the SWAMP QAPP.
QAPP Information Reference(s):
Line of Evidence (LOE) for Decision ID 23496, Titanium | Region 6
Mesquite Springs (Inyo County)
LOE ID: | 6228
Pollutant: | Titanium
LOE Subgroup: | Pollutant-Water
Matrix: | Water
Fraction: | Dissolved
Beneficial Use: | Cold Freshwater Habitat
Number of Samples: | 2
Number of Exceedances: | 0
Data and Information Type: | Fixed station physical/chemical (conventional plus toxic pollutants)
Data Used to Assess Water Quality: | The U.S. Geological Survey sampled Mesquite Springs under the Region 6 SWAMP program in 2002 and 2003. A radioactive isotope of titanium was measured. Two samples had activities of -0.2 and 0.1 picocuries per liter (pCi/L). No biological data are available for assessment of compliance with the narrative objective.
Data Reference: | 2007. SWAMP Data for the Amargosa Hydrologic Unit
SWAMP Data: | SWAMP
Water Quality Objective/Criterion: | There are no state or federal water quality standards or criteria for titanium. The Lahontan Basin Plan's narrative water quality objective for radioactivity states: "Radionuclides ahll not be present in concentrations which are deleterious to human, plant, animal or aquatic life nor which result in the accumulation of radionuclides in the food web to an extent which presents a hazard to human, plant, animal or aquatic life." The objective also references drinking water Maximum Contaminant Levels for radionuclides.
Objective/Criterion Reference: | Water Quality Control Plan for the Lahontan Region (as amended)
Evaluation Guideline: |
Guideline Reference:
Spatial Representation: | One station, Mesquite Spring (in Death Valley National Park, near Scottys Castle), was sampled.
Temporal Representation: | Two samples were collected in 2002 and 2003.
Environmental Conditions: | The Mesquite Springs are within the Stovepipe Wells Hydrologic Subarea of the Amargosa Hydrologic Unit (HU No. 609.11). They supply drinking water to a campground. No site-specific water quality objectives apply to the springs. Chemical and radioactive constituents come from natural sources.
QAPP Information: | Data meet the quality assurance requirements of the SWAMP QAPP.
QAPP Information Reference(s):

DECISION ID | 23211 | Region 6
Mesquite Springs (Inyo County)

Pollutant: | Total Dissolved Solids
Final Listing Decision: | Do Not List on 303(d) list (TMDL required list)
Last Listing Cycle's Final Listing Decision: | Do Not List on 303(d) list (TMDL required list)(2010)
Revision Status | Original
Impairment from Pollutant or Pollution: | Pollutant
Regional Board Staff Conclusion: | This pollutant was considered for placement on the section 303(d) list in a previous assessment cycle. No new information was reviewed for this current assessment cycle. Therefore, the previous conclusion remains unchanged, and is as follows: This pollutant is being considered for placement on the section 303(d) list under section 3.2 of the Listing Policy. Under section 3.2 a single line of evidence is necessary to assess listing status. One line of evidence is available in the administrative record to assess this pollutant. Neither of the samples exceeds the upper limit in the California Maximum Contaminant Level (MCL). Based on the readily available data and information, the weight of evidence indicates that there is sufficient justification against placing this water segment-pollutant combination on the section 303(d) list in the Water Quality Limited Segments category. This conclusion is based on the staff findings that: 1. The data used satisfy the data quality requirements of section 6.1.4 of the Policy. 2. The data used do not satisfy the data quantity requirements of section 6.1.5 of the Policy in that only one sample per year is available. 3. Neither of two samples exceeded the MCL and this does not exceed the allowable frequency listed in Table 3.2 of the Listing Policy. However, the minimum sample number requirements of the Listing Policy are not met. 4. Pursuant to section 3.11 of the Listing Policy, no additional data and information are available indicating that standards are not met.
Regional Board Staff Decision Recommendation: | No new data were assessed for this assessment cycle. The conclusion reached in the previous cycle remains in same. The Regional Board will update this decision when new data and information become available in a future assessment cycle.

Line of Evidence (LOE) for Decision ID 23211, Total Dissolved Solids | Region 6
Mesquite Springs (Inyo County)
LOE ID: | 5255
Pollutant: | Total Dissolved Solids
LOE Subgroup: | Pollutant-Water
Matrix: | Water
Fraction: | Total Dissolved
Beneficial Use: | Municipal & Domestic Supply
Number of Samples: | 2
Number of Exceedances: | 0
Data and Information Type: | Not Specified
Data Used to Assess Water Quality: | The U.S. Geological Survey sampled Mesquite Springs under the Region 6 SWAMP program. TDS concentrations in two samples were 827 and 820 mg/L. The recommended secondary MCL was exceeded, but the upper limit (1000 mg/L) was not. Sample numbers were too small for use with the Listing Policy's binomial model.
Data Reference: | 2007. SWAMP Data for the Amargosa Hydrologic Unit
SWAMP Data: | SWAMP
Water Quality Objective/Criterion: | California Maximum Contaminant Levels (MCLs) apply to ambient waters under the Lahontan Basin Plan's "Chemical Constituents" objective. The recommended secondary MCL for Total Dissolved Solids (TDS) is 500 mg/L; however, 1000 mg/L is acceptable as an upper limit and 1500 mg/L is acceptable as a short term value.
Objective/Criterion Reference: | Water Quality Control Plan for the Lahontan Region (as amended)
Evaluation Guideline: |
Guideline Reference:
Spatial Representation: | One station, Mesquite Spring (in Death Valley National Park, near Scottys Castle), was sampled.
Temporal Representation: | Two samples were collected in 2002 and 2003.
Environmental Conditions: | The Mesquite Springs are within the Stovepipe Wells Hydrologic Subarea of the Amargosa Hydrologic Unit (HU No. 609.11). They supply drinking water to a campground. No site-specific water quality objectives apply to the springs. Chemical and radioactive constituents, including the salts that contribute to high TDS levels, come from natural sources.
QAPP Information: | Data meet the quality assurance requirements of the SWAMP QAPP.
QAPP Information Reference(s):

DECISION ID | 23477 | Region 6
Mesquite Springs (Inyo County)

Pollutant: | Total Kjeldahl Nitrogen (TKN)
Final Listing Decision: | Do Not List on 303(d) list (TMDL required list)
Last Listing Cycle's Final Listing Decision: | Do Not List on 303(d) list (TMDL required list)(2010)
Revision Status | Original
Impairment from Pollutant or Pollution: | Pollutant
Regional Board Staff Conclusion: | This pollutant was considered for placement on the section 303(d) list in a previous assessment cycle. No new information was reviewed for this current assessment cycle. Therefore, the previous conclusion remains unchanged, and is as follows: This pollutant is being considered for placement on the section 303(d) list under section 3.1 of the Listing Policy. Under section 3.1 a single line of evidence is necessary to assess listing status One line of evidence is available in the administrative record to assess this pollutant. No biological data are available to determine whether either of the chemical samples exceeds the water quality objective for biostimulatory substances. Based on the readily available data and information, the weight of evidence indicates that there is sufficient justification against placing this water segment-pollutant combination on the section 303(d) list in the Water Quality Limited Segments category. This conclusion is based on the staff findings that: 1. The data used satisfy the data quality requirements of section 6.1.4 of the Policy. 2. The data used do not satisfy the data quantity requirements of section 6.1.5 of the Policy in that only one sample per year is available. 3. No biological data are available for assessment whether either of 2 samples exceeded the water quality objective, and the data cannot be assessed using Table 3.1 of the Listing Policy. 4. Pursuant to section 3.11 of the Listing Policy, no additional data and information are available indicating that standards are not met.
Regional Board Staff Decision Recommendation: | No new data were assessed for this assessment cycle. The conclusion reached in the previous cycle remains in same. The Regional Board will update this decision when new data and information become available in a future assessment cycle.

Line of Evidence (LOE) for Decision ID 23477, Total Kjeldahl Nitrogen (TKN) | Region 6
Mesquite Springs (Inyo County)
LOE ID: | 21247
Pollutant: | Total Kjeldahl Nitrogen (TKN)
LOE Subgroup: | Pollutant-Water
Matrix: | Water
Fraction: | Dissolved
Beneficial Use: | Cold Freshwater Habitat
Number of Samples: | 2
Number of Exceedances: | 0
Data and Information Type: | Fixed station physical/chemical (conventional plus toxic pollutants)
Data Used to Assess Water Quality: | The U.S. Geological Survey sampled Mesquite Springs under the Region 6 SWAMP program in 2002 and 2003. One of two samples for Total Kjeldahl nitrogen was below the detection level and the other was an estimated value. No information on algae growth or other secondary indicators of eutrophication is available to permit evaluation of compliance with the biostimulatory substances objective.
Data Reference: | 2007. SWAMP Data for the Amargosa Hydrologic Unit
SWAMP Data: | SWAMP
Water Quality Objective/Criterion: | There are no site-specific water quality objectives for Mesquite Springs. The Lahontan Basin Plan's narrative objective for biostimulatory substances states: "Waters shall not contain biostimulatory substances in concentrations that promote aquatic growths to the extent that such growths cause nuisance or adversely affect the water for beneficial uses."
Objective/Criterion Reference: | Water Quality Control Plan for the Lahontan Region (as amended)
Evaluation Guideline: |
Guideline Reference:
Spatial Representation: | One station, Mesquite Spring (in Death Valley National Park, near Scottys Castle), was sampled.
Temporal Representation: | Two samples were collected in 2002 and 2003.
Environmental Conditions: | The Mesquite Springs are within the Stovepipe Wells Hydrologic Subarea of the Amargosa Hydrologic Unit (HU No. 609.11). They supply drinking water to a campground. No site-specific water quality objectives apply to the springs. Chemical and radioactive constituents come from natural sources.
QAPP Information: | Data meet the quality assurance requirements of the SWAMP QAPP.
QAPP Information Reference(s):

DECISION ID | 23331 | Region 6
Mesquite Springs (Inyo County)

Pollutant: | Tritium
Final Listing Decision: | Do Not List on 303(d) list (TMDL required list)
Last Listing Cycle's Final Listing Decision: | Do Not List on 303(d) list (TMDL required list)(2010)
Revision Status | Original
Impairment from Pollutant or Pollution: | Pollutant
Regional Board Staff Conclusion: | This pollutant was considered for placement on the section 303(d) list in a previous assessment cycle. No new information was reviewed for this current assessment cycle. Therefore, the previous conclusion remains unchanged, and is as follows: This pollutant is being considered for placement on the section 303(d) list under section 3.1 of the Listing Policy. Under section 3.1 a single line of evidence is necessary to assess listing status. One line of evidence is available in the administrative record to assess this pollutant. Neither of the samples exceeds the California Maximum Contaminant Level. Based on the readily available data and information, the weight of evidence indicates that there is sufficient justification against placing this water segment-pollutant combination on the section 303(d) list in the Water Quality Limited Segments category. This conclusion is based on the staff findings that: 1. The data used satisfy the data quality requirements of section 6.1.4 of the Policy. 2. The data used do not satisfy the data quantity requirements of section 6.1.5 of the Policy in that only one sample per year is available. 3. Neither of two samples exceeded the MCL and this does not exceed the allowable frequency listed in Table 3.1 of the Listing Policy. 4. Pursuant to section 3.11 of the Listing Policy, no additional data and information are available indicating that standards are not met.
Regional Board Staff Decision Recommendation: | No new data were assessed for this assessment cycle. The conclusion reached in the previous cycle remains in same. The Regional Board will update this decision when new data and information become available in a future assessment cycle.

Line of Evidence (LOE) for Decision ID 23331, Tritium | Region 6
Mesquite Springs (Inyo County)
LOE ID: | 21281
Pollutant: | Tritium
LOE Subgroup: | Pollutant-Water
Matrix: | Water
Fraction: | None
Beneficial Use: | Municipal & Domestic Supply
Number of Samples: | 2
Number of Exceedances: | 0
Data and Information Type: | Fixed station physical/chemical (conventional plus toxic pollutants)
Data Used to Assess Water Quality: | The U.S. Geological Survey sampled Mesquite Springs under the Region 6 SWAMP program in 2002 and 2003. The reported levels of tritium 2 were 0.64 and 0.58 pCi/L. The MCL was not exceeded.
Data Reference: | 2007. SWAMP Data for the Amargosa Hydrologic Unit
SWAMP Data: | SWAMP
Water Quality Objective/Criterion: | California Maximum Contaminant Levels (MCLs) apply to ambient waters designated for the MUN use under the Lahontan Basin Plan's objective for radioactivity. The MCL for tritium is 20,000 picocuries per liter (pCi/L).
Objective/Criterion Reference: | Water Quality Control Plan for the Lahontan Region (as amended)
Evaluation Guideline: |
Guideline Reference:
Spatial Representation: | One station, Mesquite Spring (in Death Valley National Park, near Scottys Castle), was sampled.
Temporal Representation: | Two samples were collected in 2002 and 2003.
Environmental Conditions: | The Mesquite Springs are within the Stovepipe Wells Hydrologic Subarea of the Amargosa Hydrologic Unit (HU No. 609.11). They supply drinking water to a campground. No site-specific water quality objectives apply to the springs. Chemical and radioactive constituents come from natural sources.
QAPP Information: | Data meet the quality assurance requirements of the SWAMP QAPP.
QAPP Information Reference(s):

DECISION ID | 21093 | Region 6
Mesquite Springs (Inyo County)

Pollutant: | Uranium
Final Listing Decision: | Do Not List on 303(d) list (TMDL required list)
Last Listing Cycle's Final Listing Decision: | Do Not List on 303(d) list (TMDL required list)(2010)
Revision Status | Original
Impairment from Pollutant or Pollution: | Pollutant
Regional Board Staff Conclusion: | This pollutant was considered for placement on the section 303(d) list in a previous assessment cycle. No new information was reviewed for this current assessment cycle. Therefore, the previous conclusion remains unchanged, and is as follows: This pollutant is being considered for placement on the section 303(d) list under section 3.1 of the Listing Policy. Under section 3.1 a single line of evidence is necessary to assess listing status. One line of evidence is available in the administrative record to assess this pollutant. None of the samples exceed the California Maximum Contaminant Level, applicable under the Radioactivity objective. Based on the readily available data and information, the weight of evidence indicates that there is sufficient justification against placing this water segment-pollutant combination on the section 303(d) list in the Water Quality Limited Segments category. This conclusion is based on the staff findings that: 1. The data used satisfy the data quality requirements of section 6.1.4 of the Policy. 2. The data used do not satisfy the data quantity requirements of section 6.1.5 of the Policy in that only one sample per year is available. 3. Neither of two samples exceeded the Maximum Contaminant Level and this does not exceed the allowable frequency listed in Table 3.1 of the Listing Policy. 4. Pursuant to section 3.11 of the Listing Policy, no additional data and information are available indicating that standards are not met.
Regional Board Staff Decision Recommendation: | No new data were assessed for this assessment cycle. The conclusion reached in the previous cycle remains in same. The Regional Board will update this decision when new data and information become available in a future assessment cycle.

Line of Evidence (LOE) for Decision ID 21093, Uranium | Region 6
Mesquite Springs (Inyo County)
LOE ID: | 5589
Pollutant: | Uranium
LOE Subgroup: | Pollutant-Water
Matrix: | Water
Fraction: | Dissolved
Beneficial Use: | Municipal & Domestic Supply
Number of Samples: | 2
Number of Exceedances: | 0
Data and Information Type: | Fixed station physical/chemical (conventional plus toxic pollutants)
Data Used to Assess Water Quality: | The USGS sampled Mesquite Springs under the Region 6 SWAMP program. Dissolved uranium concentrations in two samples were 5.62 and 6.32 ug/L. Using the OEHHA conversion factor of 0.79 pCi per ug, based on studies of naturally occurring uranium in California, the equivalent values for the samples are 4.44 and 4.99 pCi/L. The MCL was not exceeded.
Data Reference: | 2007. SWAMP Data for the Amargosa Hydrologic Unit
| 2001. Public Health Goal for Uranium in Drinking Water. April 2001
SWAMP Data: | SWAMP
Water Quality Objective/Criterion: | California Maximum Contaminant Levels (MCLs) apply to ambient waters under the Lahontan Basin Plan's water quality objective for radioactivity. The MCL for uranium is 20 picocuries per liter (pCi/L).
Objective/Criterion Reference: | Water Quality Control Plan for the Lahontan Region (as amended)
Evaluation Guideline: |
Guideline Reference:
Spatial Representation: | One station, Mesquite Spring (in Death Valley National Park, near Scottys Castle), was sampled.
Temporal Representation: | Two samples were taken in 2002 and 2003.
Environmental Conditions: | The Mesquite Springs are within the Stovepipe Wells Hydrologic Subarea of the Amargosa Hydrologic Unit (HU No. 609.11). They supply drinking water to a campground. No site-specific water quality objectives apply to the springs. Chemical and radioactive constituents come from natural sources.
QAPP Information: | Data meet the quality assurance requirements of the SWAMP QAPP.
QAPP Information Reference(s):

DECISION ID | 23463 | Region 6
Mesquite Springs (Inyo County)

Pollutant: | Vanadium
Final Listing Decision: | Do Not List on 303(d) list (TMDL required list)
Last Listing Cycle's Final Listing Decision: | Do Not List on 303(d) list (TMDL required list)(2010)
Revision Status | Original
Impairment from Pollutant or Pollution: | Pollutant
Regional Board Staff Conclusion: | This pollutant was considered for placement on the section 303(d) list in a previous assessment cycle. No new information was reviewed for this current assessment cycle. Therefore, the previous conclusion remains unchanged, and is as follows: This pollutant is being considered for placement on the section 303(d) list under section 3.1 of the Listing Policy. Under section 3.1 a single line of evidence is necessary to assess listing status. Two lines of evidence are available in the administrative record to assess this pollutant. There are no applicable water quality standards or criteria for protection of aquatic life. None of the samples exceeds the California Maximum Contaminant Level (MCL). Based on the readily available data and information, the weight of evidence indicates that there is sufficient justification against placing this water segment-pollutant combination on the section 303(d) list in the Water Quality Limited Segments category. This conclusion is based on the staff findings that: 1. The data used satisfy the data quality requirements of section 6.1.4 of the Policy. 2. The data used do not satisfy the data quantity requirements of section 6.1.5 of the Policy in that only one sample per year is available. 3. Neither of two samples exceeded the MCL and this does not exceed the allowable frequency listed in Table 3.1 of the Listing Policy. 4. Pursuant to section 3.11 of the Listing Policy, no additional data and information are available indicating that standards are not met.
Regional Board Staff Decision Recommendation: | No new data were assessed for this assessment cycle. The conclusion reached in the previous cycle remains in same. The Regional Board will update this decision when new data and information become available in a future assessment cycle.

Line of Evidence (LOE) for Decision ID 23463, Vanadium | Region 6
Mesquite Springs (Inyo County)
LOE ID: | 21289
Pollutant: | Vanadium
LOE Subgroup: | Pollutant-Water
Matrix: | Water
Fraction: | Dissolved
Beneficial Use: | Municipal & Domestic Supply
Number of Samples: | 2
Number of Exceedances: | 0
Data and Information Type: | Fixed station physical/chemical (conventional plus toxic pollutants)
Data Used to Assess Water Quality: | The U.S. Geological Survey sampled Mesquite Springs under the Region 6 SWAMP program in 2002 and 2003. The reported concentrations of dissolved vanadium in 2 samples were 14.9 and 14.3 ug/L. The MCL was not exceeded.
Data Reference: | 2007. SWAMP Data for the Amargosa Hydrologic Unit
SWAMP Data: | SWAMP
Water Quality Objective/Criterion: | California Maximum Contaminant Levels (MCLs) apply to ambient waters under the Lahontan Basin Plan's "Chemical Constituents" objective. The MCL for vanadium is 50 ug/L.
Objective/Criterion Reference: | Water Quality Control Plan for the Lahontan Region (as amended)
Evaluation Guideline: |
Guideline Reference:
Spatial Representation: | One station, Mesquite Spring (in Death Valley National Park, near Scottys Castle), was sampled.
Temporal Representation: | Two samples were collected in 2002 and 2003.
Environmental Conditions: | The Mesquite Springs are within the Stovepipe Wells Hydrologic Subarea of the Amargosa Hydrologic Unit (HU No. 609.11). They supply drinking water to a campground. No site-specific water quality objectives apply to the springs. Chemical and radioactive constituents come from natural sources.
QAPP Information: | Data meet the quality assurance requirements of the SWAMP QAPP.
QAPP Information Reference(s):
Line of Evidence (LOE) for Decision ID 23463, Vanadium | Region 6
Mesquite Springs (Inyo County)
LOE ID: | 21290
Pollutant: | Vanadium
LOE Subgroup: | Pollutant-Water
Matrix: | Water
Fraction: | Dissolved
Beneficial Use: | Cold Freshwater Habitat
Number of Samples: | 2
Number of Exceedances: | 0
Data and Information Type: | Fixed station physical/chemical (conventional plus toxic pollutants)
Data Used to Assess Water Quality: | The U.S. Geological Survey sampled Mesquite Springs under the Region 6 SWAMP program in 2002 and 2003. The reported concentrations of dissolved vanadium in 2 samples were 14.9 and 14.3 ug/L.
Data Reference: | 2007. SWAMP Data for the Amargosa Hydrologic Unit
SWAMP Data: | SWAMP
Water Quality Objective/Criterion: | There are no applicable state or federal standards or criteria for vanadium for the protection of aquatic life.
Objective/Criterion Reference: | Water Quality Control Plan for the Lahontan Region (as amended)
Evaluation Guideline: |
Guideline Reference:
Spatial Representation: | One station, Mesquite Spring (in Death Valley National Park, near Scottys Castle), was sampled.
Temporal Representation: | Two samples were collected in 2002 and 2003.
Environmental Conditions: | The Mesquite Springs are within the Stovepipe Wells Hydrologic Subarea of the Amargosa Hydrologic Unit (HU No. 609.11). They supply drinking water to a campground. No site-specific water quality objectives apply to the springs. Chemical and radioactive constituents come from natural sources.
QAPP Information: | Data meet the quality assurance requirements of the SWAMP QAPP.
QAPP Information Reference(s):

DECISION ID | 21021 | Region 6
Mesquite Springs (Inyo County)

Pollutant: | Zinc
Final Listing Decision: | Do Not List on 303(d) list (TMDL required list)
Last Listing Cycle's Final Listing Decision: | Do Not List on 303(d) list (TMDL required list)(2010)
Revision Status | Original
Impairment from Pollutant or Pollution: | Pollutant
Regional Board Staff Conclusion: | This pollutant was considered for placement on the section 303(d) list in a previous assessment cycle. No new information was reviewed for this current assessment cycle. Therefore, the previous conclusion remains unchanged, and is as follows: This pollutant is being considered for placement on the section 303(d) list under section 3.1 of the Listing Policy. Under section 3.1 a single line of evidence is necessary to assess listing status. Two lines of evidence are available in the administrative record to assess this pollutant. None of the samples exceeds the applicable water quality objectives. Based on the readily available data and information, the weight of evidence indicates that there is sufficient justification against placing this water segment-pollutant combination on the section 303(d) list in the Water Quality Limited Segments category. This conclusion is based on the staff findings that: 1. The data used satisfy the data quality requirements of section 6.1.4 of the Policy. 2. The data used do not satisfy the data quantity requirements of section 6.1.5 of the Policy in that only one sample per year is available. 3. Neither of two samples exceeded the applicable objectives and this does not exceed the allowable frequency listed in Table 3.1 of the Listing Policy. 4. Pursuant to section 3.11 of the Listing Policy, no additional data and information are available indicating that standards are not met.
Regional Board Staff Decision Recommendation: | No new data were assessed for this assessment cycle. The conclusion reached in the previous cycle remains in same. The Regional Board will update this decision when new data and information become available in a future assessment cycle.

Line of Evidence (LOE) for Decision ID 21021, Zinc | Region 6
Mesquite Springs (Inyo County)
LOE ID: | 5318
Pollutant: | Zinc
LOE Subgroup: | Pollutant-Water
Matrix: | Water
Fraction: | Dissolved
Beneficial Use: | Municipal & Domestic Supply
Number of Samples: | 2
Number of Exceedances: | 0
Data and Information Type: | Fixed station physical/chemical (conventional plus toxic pollutants)
Data Used to Assess Water Quality: | The U.S. Geological Survey sampled Mesquite Springs under the Region 6 SWAMP program in 2002 and 2003. One of two dissolved zinc samples was below the detection level and zinc in the other was detected but not quantified (USGS Code M) The MCL was not exceeded. (Note: MCLs for metals are expressed as total rather than dissolved, but only dissolved zinc data were available.)
Data Reference: | 2007. SWAMP Data for the Amargosa Hydrologic Unit
SWAMP Data: | SWAMP
Water Quality Objective/Criterion: | California Maximum Contaminant Levels (MCLs) apply to ambient waters under the Lahontan Basin Plan's "Chemical Constituents" objective. The MCL for zinc is 5000 ug/L.
Objective/Criterion Reference: | Water Quality Control Plan for the Lahontan Region (as amended)
Evaluation Guideline: |
Guideline Reference:
Spatial Representation: | One station, Mesquite Spring (in Death Valley National Park, near Scottys Castle), was sampled.
Temporal Representation: | Two samples were collected in 2002 and 2003.
Environmental Conditions: | The Mesquite Springs are within the Stovepipe Wells Hydrologic Subarea of the Amargosa Hydrologic Unit (HU No. 609.11). They supply drinking water to a campground. No site-specific water quality objectives apply to the springs. Chemical and radioactive constituents come from natural sources.
QAPP Information: | Data meet the quality assurance requirements of the SWAMP QAPP.
QAPP Information Reference(s):
Line of Evidence (LOE) for Decision ID 21021, Zinc | Region 6
Mesquite Springs (Inyo County)
LOE ID: | 5320
Pollutant: | Zinc
LOE Subgroup: | Pollutant-Water
Matrix: | Water
Fraction: | Dissolved
Beneficial Use: | Cold Freshwater Habitat
Number of Samples: | 2
Number of Exceedances: | 0
Data and Information Type: | Fixed station physical/chemical (conventional plus toxic pollutants)
Data Used to Assess Water Quality: | The U.S. Geological Survey sampled Mesquite Springs under the Region 6 SWAMP program in 2002 and 2003.One of two dissolved zinc samples was below the detection level and zinc in the other was detected but not quantified. The CTR standards were not violated.
Data Reference: | 2007. SWAMP Data for the Amargosa Hydrologic Unit
SWAMP Data: | SWAMP
Water Quality Objective/Criterion: | The California Toxics Rule zinc standards for protection of freshwater aquatic life are dependent on hardness. At the reported hardness levels, the acute toxicity standard for zinc ranges from 139.65 to 142.53 ug/L, and the chronic toxicity standard ranges from 140.79 to 143.69 ug/L.
Objective/Criterion Reference: | Water Quality Standards 2000. Establishment of numeric criteria for priority toxic pollutants for the State of California: Rules and regulations. Federal Register Vol. 65, No. 97. Washington, D.C.: Environmental Protection Agency
Evaluation Guideline: |
Guideline Reference:
Spatial Representation: | One station, Mesquite Spring (in Death Valley National Park, near Scottys Castle), was sampled.
Temporal Representation: | Two samples were collected in 2002 and 2003.
Environmental Conditions: | The Mesquite Springs are within the Stovepipe Wells Hydrologic Subarea of the Amargosa Hydrologic Unit (HU No. 609.11). They supply drinking water to a campground. No site-specific water quality objectives apply to the springs. Chemical and radioactive constituents come from natural sources.
QAPP Information: | Data meet the quality assurance requirements of the SWAMP QAPP.
QAPP Information Reference(s):

DECISION ID | 20931 | Region 6
Mesquite Springs (Inyo County)

Pollutant: | pH
Final Listing Decision: | Do Not List on 303(d) list (TMDL required list)
Last Listing Cycle's Final Listing Decision: | Do Not List on 303(d) list (TMDL required list)(2010)
Revision Status | Original
Impairment from Pollutant or Pollution: | Pollutant
Regional Board Staff Conclusion: | This pollutant was considered for placement on the section 303(d) list in a previous assessment cycle. No new information was reviewed for this current assessment cycle. Therefore, the previous conclusion remains unchanged, and is as follows: Two lines of evidence are available in the administrative record to assess this pollutant. For waters designated for the Cold Freshwater Habitat beneficial use,the Lahontan Basin Plan's narrative pH objective is a non-degradation objective, and sample numbers are insufficient to establish baseline conditions or detect trends as required under Listing Policy Section 3.10. Based on the readily available data and information, the weight of evidence indicates that there is sufficient justification against placing this water segment-pollutant combination on the section 303(d) list in the Water Quality Limited Segments category. This conclusion is based on the staff findings that: 1. The data used satisfy the data quality requirements of section 6.1.4 of the Policy. 2. The data used do not satisfy the data quantity requirements of section 6.1.5 of the Policy in that only one sample per year is available. 3. It is not possible to determine whether the narrative pH objective was exceeded because the requirements of Listing Policy Section 3.10 were not met. 4. Pursuant to section 3.11 of the Listing Policy, no additional data and information are available indicating that standards are not met.
Regional Board Staff Decision Recommendation: | No new data were assessed for this assessment cycle. The conclusion reached in the previous cycle remains in same. The Regional Board will update this decision when new data and information become available in a future assessment cycle.

Line of Evidence (LOE) for Decision ID 20931, pH | Region 6
Mesquite Springs (Inyo County)
LOE ID: | 5235
Pollutant: | pH
LOE Subgroup: | Pollutant-Water
Matrix: | Water
Fraction: | None
Beneficial Use: | Cold Freshwater Habitat
Number of Samples: | 4
Number of Exceedances: | 0
Data and Information Type: | Fixed station physical/chemical (conventional plus toxic pollutants)
Data Used to Assess Water Quality: | The U.S. Geological Survey sampled Mesquite Springs under the Region 6 SWAMP program. Two field pH measurements were both 7.9 units; two laboratory measurements were 8.1 and 7.9 units. Sample numbers were too small for use with the Listing Policy's binomial model, and were also too small to define normal pH levels or to detect change.
Data Reference: | 2007. SWAMP Data for the Amargosa Hydrologic Unit
SWAMP Data: | SWAMP
Water Quality Objective/Criterion: | The Lahontan Basin Plan's pH objective states: "In fresh waters with designated beneficial uses of COLD or WARM, changes in normal ambient pH levels shall not exceed 0.5 pH units. For all other waters of the region, the pH shall not be depressed below 6.5 nor raised above 8.5 units. The Regional Board recognizes that some waters of the Region may have natural pH levels outside of the 6.5 to 8.5 range. Compliance with the pH objective for these waters will be determined on a case-by-case basis."
Objective/Criterion Reference: | Water Quality Control Plan for the Lahontan Region (as amended)
Evaluation Guideline: |
Guideline Reference:
Spatial Representation: | One station, Mesquite Spring (in Death Valley National Park, near Scottys Castle), was sampled.
Temporal Representation: | Two field measurements and two laboratory measurements of pH were taken in 2002 and 2003.
Environmental Conditions: | The Mesquite Springs are within the Stovepipe Wells Hydrologic Subarea of the Amargosa Hydrologic Unit (HU No. 609.11). They supply drinking water to a campground. No site-specific water quality objectives apply to the springs. Chemical and radioactive constituents, including the salts that contribute to high specific conductance levels, come from natural sources. The Mesquite Springs are designated for both the Warm Freshwater Habitat and Cold Freshwater Habitat beneficial uses, and for the Rare, Threatened or Endangered Species Use.
QAPP Information: | Data meet the quality assurance requirements of the SWAMP QAPP.
QAPP Information Reference(s):
Line of Evidence (LOE) for Decision ID 20931, pH | Region 6
Mesquite Springs (Inyo County)
LOE ID: | 5803
Pollutant: | pH
LOE Subgroup: | Pollutant-Water
Matrix: | Water
Fraction: | None
Beneficial Use: | Municipal & Domestic Supply
Number of Samples: | 4
Number of Exceedances: | 0
Data and Information Type: | Fixed station physical/chemical (conventional plus toxic pollutants)
Data Used to Assess Water Quality: | The U.S. Geological Survey sampled Mesquite Springs under the Region 6 SWAMP program. Two field pH measurements were both 7.9 units; two laboratory measurements were 8.1 and 7.9 units. Sample numbers were too small for use with the Listing Policy's binomial model, and were also too small to define normal pH levels or to detect change.
Data Reference: | 2007. SWAMP Data for the Amargosa Hydrologic Unit
SWAMP Data: | SWAMP
Water Quality Objective/Criterion: | The U.S. Environmental Protection Agency's secondary drinking water Maximum Contaminant Level (MCL) criterion is a pH range of 6.5 to 8.5 units. (There is no California MCL for pH.)
Objective/Criterion Reference: | Compilation of Water Quality Goals
Evaluation Guideline: |
Guideline Reference:
Spatial Representation: | One station, Mesquite Spring (in Death Valley National Park, near Scottys Castle), was sampled.
Temporal Representation: | Two field measurements and two laboratory measurements of pH were taken in 2002 and 2003.
Environmental Conditions: | The Mesquite Springs are within the Stovepipe Wells Hydrologic Subarea of the Amargosa Hydrologic Unit (HU No. 609.11). They supply drinking water to a campground. No site-specific water quality objectives apply to the springs. Chemical and radioactive constituents come from natural sources.
QAPP Information: | Data meet the quality assurance requirements of the SWAMP QAPP.
QAPP Information Reference(s):

DECISION ID | 28314 | Region 6
Mesquite Springs (Inyo County)

Pollutant: | Arsenic
Final Listing Decision: | List on 303(d) list (TMDL required list)
Last Listing Cycle's Final Listing Decision: | List on 303(d) list (TMDL required list)(2010)
Revision Status | Original
Sources: | Source Unknown
Expected TMDL Completion Date: | 2021
Impairment from Pollutant or Pollution: | Pollutant
Regional Board Staff Conclusion: | Regional Board Conclusion: This pollutant was considered for placement on the section 303(d) list in a previous listing cycle. No new information was reviewed for this current assessment cycle. Therefore, the previous conclusion remains unchanged, and is as follows: This pollutant is being considered for placement on the section 303(d) list under section 3.1 of the Listing Policy. Under section 3.1 a single line of evidence is necessary to assess listing status. Two lines of evidence are available in the administrative record to assess this pollutant. Neither of the samples exceeds the California Toxics Rule aquatic life standards. Both of the samples exceed the California Maximum Contaminant Level (MCL). Although only one sample per year is available, the springs are from a groundwater source and water quality is expected to be more constant over time than the quality of a lake or stream. Listing is being recommended because the springs are an existing source of drinking water. Based on the readily available data and information, the weight of evidence indicates that there is sufficient justification in favor of placing this water segment-pollutant combination on the section 303(d) list in the Water Quality Limited Segments category. This conclusion is based on the staff findings that: 1. The data used satisfy the data quality requirements of section 6.1.4 of the Policy. 2. The data used satisfy the data quantity requirements of section 6.1.5 of the Policy. Two of two samples exceed the MCL and this exceeds the allowable frequency listed in Table 3.1 of the Listing Policy. 4. Pursuant to section 3.11 of the Listing Policy, no additional data and information are available indicating that standards are not met.
Regional Board Staff Decision Recommendation: | No new data were assessed for this assessment cycle. The conclusion reached in the previous cycle remains the same. The Regional Board will update this decision when new data and information become available in a future assessment cycle.

Line of Evidence (LOE) for Decision ID 28314, Arsenic | Region 6
Mesquite Springs (Inyo County)
LOE ID: | 5269
Pollutant: | Arsenic
LOE Subgroup: | Pollutant-Water
Matrix: | Water
Fraction: | Dissolved
Beneficial Use: | Municipal & Domestic Supply
Number of Samples: | 2
Number of Exceedances: | 2
Data and Information Type: | Not Specified
Data Used to Assess Water Quality: | The U.S. Geological Survey sampled Mesquite Springs under the Region 6 SWAMP program. Arsenic concentrations in two samples were 42.5 and 35.4 ug/L. Both samples exceeded the MCL.
Data Reference: | 2007. SWAMP Data for the Amargosa Hydrologic Unit
SWAMP Data: | SWAMP
Water Quality Objective/Criterion: | California Maximum Contaminant Levels (MCLs) apply to ambient waters under the Lahontan Basin Plan's "Chemical Constituents" objective. The MCL for arsenic is 10 ug/L (effective November 28, 2008).
Objective/Criterion Reference: | Water Quality Control Plan for the Lahontan Region (as amended)
Evaluation Guideline: |
Guideline Reference:
Spatial Representation: | One station, Mesquite Spring (in Death Valley National Park, near Scottys Castle), was sampled.
Temporal Representation: | Two samples were collected in 2002 and 2003.
Environmental Conditions: | The Mesquite Springs are within the Stovepipe Wells Hydrologic Subarea of the Amargosa Hydrologic Unit (HU No. 609.11). They supply drinking water to a campground. No site-specific water quality objectives apply to the springs. Chemical and radioactive constituents, including arsenic, come from natural sources.
QAPP Information: | Data meet the quality assurance requirements of the SWAMP QAPP.
QAPP Information Reference(s):
Line of Evidence (LOE) for Decision ID 28314, Arsenic | Region 6
Mesquite Springs (Inyo County)
LOE ID: | 5791
Pollutant: | Arsenic
LOE Subgroup: | Pollutant-Water
Matrix: | Water
Fraction: | Dissolved
Beneficial Use: | Cold Freshwater Habitat
Number of Samples: | 2
Number of Exceedances: |
Data and Information Type: | Not Specified
Data Used to Assess Water Quality: | The U.S. Geological Survey sampled Mesquite Springs under the Region 6 SWAMP program. Arsenic concentrations in two samples were 42.5 and 35.4 ug/L. The California Toxics Rule standards were not exceeded.
Data Reference: | 2007. SWAMP Data for the Amargosa Hydrologic Unit
SWAMP Data: | SWAMP
Water Quality Objective/Criterion: | The California Toxics Rule's freshwater aquatic life standards for arsenic are as follows: 4 day average = 150 ug/l; 1 hour average = 340 ug/L.
Objective/Criterion Reference: | Water Quality Standards 2000. Establishment of numeric criteria for priority toxic pollutants for the State of California: Rules and regulations. Federal Register Vol. 65, No. 97. Washington, D.C.: Environmental Protection Agency
Evaluation Guideline: |
Guideline Reference:
Spatial Representation: | One station, Mesquite Spring (in Death Valley National Park, near Scottys Castle), was sampled.
Temporal Representation: | Two samples were collected in 2002 and 2003.
Environmental Conditions: | The Mesquite Springs are within the Stovepipe Wells Hydrologic Subarea of the Amargosa Hydrologic Unit (HU No. 609.11). They supply drinking water to a campground. No site-specific water quality objectives apply to the springs. Chemical and radioactive constituents, including arsenic, come from natural sources.
QAPP Information: | Data meet the quality assurance requirements of the SWAMP QAPP.
QAPP Information Reference(s):

DECISION ID | 23187 | Region 6
Mesquite Springs (Inyo County)

Pollutant: | Boron
Final Listing Decision: | List on 303(d) list (TMDL required list)
Last Listing Cycle's Final Listing Decision: | List on 303(d) list (TMDL required list)(2010)
Revision Status | Original
Sources: | Source Unknown
Expected TMDL Completion Date: | 2021
Impairment from Pollutant or Pollution: | Pollutant
Regional Board Staff Conclusion: | Regional Board Conclusion: This pollutant was considered for placement on the section 303(d) list in a previous listing cycle. No new information was reviewed for this current assessment cycle. Therefore, the previous conclusion remains unchanged, and is as follows: This pollutant is being considered for placement on the section 303(d) list under section 3.1 of the Listing Policy. Under section 3.1 a single line of evidence is necessary to assess listing status. One line of evidence is available in the administrative record to assess this pollutant. Both of the samples exceed the water quality objective. Although only one sample per year is available, the springs come from a groundwater source with water quality expected to be less variable over time than the quality of a stream or lake. Listing is being recommended because the springs are an existing source of drinking water. Based on the readily available data and information, the weight of evidence indicates that there is sufficient justification in favor of placing this water segment-pollutant combination on the section 303(d) list in the Water Quality Limited Segments category. This conclusion is based on the staff findings that: 1. The data used satisfy the data quality requirements of section 6.1.4 of the Policy. 2. The data used satisfy the data quantity requirements of section 6.1.5 of the Policy. 3. Two of two samples exceed the California Maximum Contaminant Level and this exceeds the allowable frequency listed in Table 3.1 of the Listing Policy. 4. Pursuant to section 3.11 of the Listing Policy, no additional data and information are available indicating that standards are not met.
Regional Board Staff Decision Recommendation: | No new data were assessed for this assessment cycle. The conclusion reached in the previous cycle remains the same. The Regional Board will update this decision when new data and information become available in a future assessment cycle.

Line of Evidence (LOE) for Decision ID 23187, Boron | Region 6
Mesquite Springs (Inyo County)
LOE ID: | 5806
Pollutant: | Boron
LOE Subgroup: | Pollutant-Water
Matrix: | Water
Fraction: | Dissolved
Beneficial Use: | Municipal & Domestic Supply
Number of Samples: | 2
Number of Exceedances: | 2
Data and Information Type: | Fixed station physical/chemical (conventional plus toxic pollutants)
Data Used to Assess Water Quality: | The U.S. Geological Survey sampled Mesquite Springs under the Region 6 SWAMP program. Boron concentrations in two samples were 1280 and 1460 ug/L, both exceeding the criterion.
Data Reference: | 2007. SWAMP Data for the Amargosa Hydrologic Unit
SWAMP Data: | SWAMP
Water Quality Objective/Criterion: | The California Department of Health Services "Notification Level for Drinking Water " criterion for boron is 1000 ug/L. This is a health-based criterion that applies to drinking water systems.
Objective/Criterion Reference: | Compilation of Water Quality Goals
Evaluation Guideline: |
Guideline Reference:
Spatial Representation: | One station, Mesquite Spring (in Death Valley National Park, near Scottys Castle), was sampled.
Temporal Representation: | Two samples were collected in 2002 and 2003.
Environmental Conditions: | The Mesquite Springs are within the Stovepipe Wells Hydrologic Subarea of the Amargosa Hydrologic Unit (HU No. 609.11). They supply drinking water to a campground. No site-specific water quality objectives apply to the springs. Chemical and radioactive constituents come from natural sources.
QAPP Information: | Data meet the quality assurance requirements of the SWAMP QAPP.
QAPP Information Reference(s):